fix(scheduler): rotate lead user each pass so caption budget is shared

Caption fetches share one per-egress-IP rate budget; whoever runs first each pass
spends the pre-throttle window before YouTube starts 429ing. ListAllUsers order
is unspecified and was stable, so the last-listed user was permanently starved —
a friendly-pilot user got 0 fetches in 12h (all rate_limited) while the
first-listed user got every successful fetch. rotateUsers left-rotates the user
order by pass index so each user leads 1/N passes and the lead slot is shared.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

CLAUDE.md

@@ -46,8 +46,9 @@ These caused real mistakes that were caught and corrected; the corrections are l
 (See `DECISIONS.md` for full rationale. Listed here so you don't propose them.)
 
 - **No Supabase** — reuse Dex / ESO+1Password / Postgres (ADR-002).
-- **No global cross-tenant video/transcript table** — per-user isolation (data-model). Dedup
+- **No global cross-tenant *video* table** — videos stay per-user (data-model). Transcripts ARE
-  across users is a Future C concern, not a Stage 0/1 default.
+  shared since ADR-021 (public caption content, keyed by `(provider, provider_video_id)`, non-RLS)
+  so re-analysis never re-fetches; the *videos* half of cross-tenant dedup stays a Future C concern.
 - **No audio-download + speech-to-text in the core path** — captions-first (ADR-007). STT is a
   deferred, bounded optional component.
 - **No public SaaS / sign-up / billing / Google OAuth verification at scale** — Future C,
@@ -85,7 +86,7 @@ Skills live in the canonical library `mathias/skills` and are wired into this re
 
 ## Current build state (start here for the first task)
 
-The repo is **green and shipping** — last tag `v0.9.0`. `task check` passes (fmt, vet, lint,
+The repo is **green and shipping** — last tag `v0.15.0`. `task check` passes (fmt, vet, lint,
 `go test -p 1 ./...`). Go is `1.26.1` (see `go.mod`).
 
 - Clean Architecture core is implemented: `internal/domain` (entities), `internal/ports`
@@ -94,13 +95,19 @@ The repo is **green and shipping** — last tag `v0.9.0`. `task check` passes (f
   green against it.
 - Adapters present under `internal/adapters/`: `youtube` (captions-first `VideoSource`,
   timedtext/InnerTube acquisition per ADR-010), `summarizer` + `llm` (the copied AI router,
-  Primary→Fallback per ADR-004), `store` (Postgres, golang-migrate migrations 001–006),
+  now a resilient endpoint chain — local primary → local fallback → external worst-case,
+  parse-failure-aware, ADR-004 + ADR-022), `store` (Postgres, golang-migrate migrations 001–015),
   `secrets` (file-backed `SecretStore`). The brain HTTP sink (ADR-005) is the remaining
   optional sink.
 - Stage 1 is open (ADR-012): multi-user with **DB-enforced** isolation — Postgres RLS `FORCE`d
   on all user-owned tables (migration 003), two-user isolation test in
   `internal/adapters/store/rls_test.go`. Registration gate, per-user YouTube web connect, and
   account management (disconnect / delete, ADR-013) all shipped.
+- Transcript persistence (ADR-021, migration 015): transcripts are a **shared, non-RLS** store
+  keyed by `(provider, provider_video_id)` — the single exception to the isolation boundary
+  (`TestTranscriptsTableIsSharedNotRLS`). The engine reads stored transcripts before any caption
+  fetch (`usecase.resolveTranscript`), so re-analysis — re-summarize, paste-a-URL, onboarding
+  burst — never re-touches YouTube. Per-user summaries/videos stay RLS-scoped.
 - `cmd/tapir` subcommands: `list`, `show`, `auth` (interactive host-side OAuth), `run` (batch
   watch→summarize), `serve` (the HTMX+Templ web reader/writer under `internal/web`, a new
   transport over the unchanged engine/ports — ADR-003). `tapir env` prints config.

DECISIONS.md

@@ -743,6 +743,118 @@ collapse keys off the same window (`App.RecencyWindow=0` → everything inline).
 
 ---
 
+## ADR-021 — Persist transcripts as shared, video-keyed public content (re-analysis never re-fetches)
+
+**Status:** Accepted (2026-06-09). **Reopens the transcripts half of** the "Global cross-tenant
+`videos`/`transcripts` table" rejection (data-model.md). **Builds on ADR-007** (captions-first),
+**ADR-010/ADR-014** (the per-IP caption rate gate), and **ADR-012** (per-user RLS isolation).
+
+**Context.** Every summarization fetches the transcript fresh through the caption path, even when
+the exact same transcript was fetched moments ago — for the same user re-summarizing, or for a
+second user who happens to watch the same video. The caption fetch is the one genuinely scarce,
+genuinely risky operation in the system: YouTube's timedtext endpoint is unofficial and per-IP
+rate-limited (ADR-010), and tripping it risks the maintainer's Google standing (ADR-014). So the
+operation we most want to *avoid repeating* is the one we currently repeat unconditionally. A
+transcript is **public content** — the same words YouTube serves to anyone — and carries nothing
+user-identifying. The per-user isolation that protects summaries, feeds, and tokens (ADR-012) is
+the wrong shape for it: it forces a re-fetch per user for data that is identical across users.
+
+The original rejection ("Global cross-tenant `videos`/`transcripts` table") bundled videos and
+transcripts together and rejected both on the grounds that "at 1–5 users, re-summarizing is
+cheaper than the coupling." That reasoning holds for **videos** (per-user feed rows, genuinely
+user-scoped) but not for **transcripts**: the cost being avoided is not LLM re-summarization, it
+is a *rate-gated, reputation-risky network fetch*, and that cost is paid per re-fetch regardless
+of user count. One re-fetch avoided is strictly worth more than the coupling it removes.
+
+**Decision.**
+1. **A single shared `transcripts` table, keyed by the cross-user dedup key
+   `(provider, provider_video_id)`** — the stable public identity of the video, not Tapir's
+   internal per-user `videos.id`. Columns: the key, `source` (`captions`/`none`), `language`,
+   `content`, `fetched_at`. It holds **only public caption content + the video's public id** —
+   nothing user-identifying — and is therefore **NOT RLS-scoped**: no `user_id`, no policy, no
+   `FORCE ROW LEVEL SECURITY`. This is the deliberate, single exception to the ADR-012 isolation
+   boundary, and the only one.
+2. **Summarize path becomes read-stored-first.** Have a stored transcript for this video? →
+   summarize from the stored text, **no caption fetch**. No stored transcript? → fetch *through
+   the unchanged gate* (ADR-014) → store it → summarize. The gate is neither bypassed nor
+   weakened; persistence reduces how *often* we reach it, never how *fast*.
+3. **De-facto cross-user dedup is the intended behaviour, not a feature with a switch.** Two
+   users who share a video share the one transcript row. A permanent `source = 'none'` (no
+   captions) is stored too, so a known-caption-less video is not re-fetched by anyone. A
+   transient 429 (`SourceRateLimited`) is **never** stored as terminal — it stays a per-user
+   retry via the existing `transcript_status` backoff (ADR-014), so persistence cannot mask a
+   rate-limit into a false "no transcript."
+4. **Per-user `summaries` stay RLS-scoped (ADR-012 unchanged)** and reference the transcript by
+   video id. Videos stay per-user. Only transcripts go shared.
+
+**Consequences.** Re-analysis (re-summarize, different model, paste of an already-seen video,
+onboarding of a second user with overlapping subscriptions) never re-touches YouTube — the
+primary win, and it *reduces* aggregate caption-gate pressure, reinforcing ADR-010/ADR-014 rather
+than straining them. The isolation surface gains exactly one non-RLS table; an isolation test
+asserts the boundary is *exactly* there and has not leaked to any user-owned table (this is the
+proof the public-content classification was implemented as designed). It also unblocks
+multi-model / customizable analysis (re-run analysis on stored text for free) — enabling that is
+this ADR's point; building it is separate.
+
+**Reversibility.** The read-stored-first check is the only behavioural coupling; removing it
+restores fetch-every-time. The down-migration recreates the per-user RLS-scoped transcripts shape
+(001/003). No user-facing surface depends on cross-user sharing — sharing is the *storage shape*,
+never exposed in the UI.
+
+---
+
+## ADR-022 — Summarizer is a resilient endpoint chain, not a single model
+
+**Status:** Accepted (2026-06-10). **Extends ADR-004** (the copied `llm` Primary→Fallback
+routing). Triggered by the first friendly-pilot live run, where a connected user got **zero**
+summaries after 12h.
+
+**Context.** Stage-0 ran a single summarizer model (`koala/phi4-mini`) with no fallback wired
+(`summarizer.New(primary, nil)`). The live run exposed three independent failure modes, each of
+which silently produced no summary:
+
+1. **Context overflow.** `phi4-mini` has an 8k context. Real transcripts (one was 11,602 tokens)
+   exceed it and the gateway returns HTTP 400 — and the request also sent `max_tokens=8192`, so
+   even a short transcript plus the completion budget could overflow the window.
+2. **Malformed model output.** `phi4-mini` intermittently emits `highlights` as a bare string
+   instead of an array, producing `cannot unmarshal string into []string`. The old code returned
+   the parse error **without** trying any other model — a 200-with-bad-JSON short-circuited.
+3. **No fallback existed at all** — any primary failure was terminal for that video.
+
+`phi4-mini` is kept as primary deliberately: it is fast and, on transcripts that fit, correct.
+The fix is resilience around it, not replacing it.
+
+**Decision.**
+1. **Ordered endpoint chain (`summarizer.NewChain`).** Endpoints are tried in order; the first to
+   return a *parseable* summary wins. Default chain:
+   `koala/phi4-mini` (primary, local) → `koala/phi4-14b` (fallback, local) →
+   `berget/mistral-small` (worst-case, external). All three are reached through the **one** LiteLLM
+   gateway by alias — the gateway already fronts both llama-swap and berget — so a fallback is a
+   different alias, not a second client config.
+2. **A parse failure advances the chain, same as a transport error.** "Reliably summarized" means
+   *parseable summary returned*, not *HTTP 200*. This is the behaviour the old Primary→Fallback
+   shape missed.
+3. **Tolerant parse.** `highlights`/`takeaways` coerce from a bare string (or a mixed scalar
+   array) to `[]string`, so the most common small-model quirk is absorbed **without** spending a
+   fallback round-trip — keeping the fast path fast.
+4. **Transcript truncation (`TAPIR_MAX_TRANSCRIPT_CHARS`, default 18000).** Input is bounded
+   up-front to fit a small-context primary, so overflow is prevented rather than recovered-from.
+5. **Bounded completion budget (`TAPIR_SUMMARY_MAX_TOKENS`, default 1500).** A summary needs few
+   hundred tokens; the old 8192 budget itself contributed to 8k-window overflow.
+
+**Local-first guarantee preserved.** The chain ordering *is* the guarantee: locals are tried
+first, so content reaches the external endpoint only after every local endpoint has failed.
+`TAPIR_CLOUD_FALLBACK_MODEL=""` removes the external endpoint entirely — the lever a
+**client/NDA deployment** pulls so content never leaves the local stack. With no external endpoint
+configured the `ai_routing.feature` "content only local" scenarios hold unchanged.
+
+**Reversibility.** Pure wiring + config. Setting `TAPIR_FALLBACK_MODEL` and
+`TAPIR_CLOUD_FALLBACK_MODEL` empty collapses the chain back to single-primary behaviour; the
+tolerant parse and truncation are strict supersets of the old behaviour (a previously-parseable
+reply still parses; a transcript within budget is unchanged).
+
+---
+
 ## Rejected alternatives
 
 Approaches considered during the 2026-06-02 planning + grill session and **deliberately not
@@ -757,7 +869,7 @@ maps to the ADR that settles it.
 | Lifting shared packages into a `brain-common` module | Couples Tapir's release cycle to the monolith for negligible code savings | ADR-004 |
 | Importing/replicating the filesystem `brain` package | Assumes co-location with the brain git checkout; wrong for a standalone networked service | ADR-005 |
 | Reusing `ingestion`'s `oauth` package for YouTube/Vimeo | Same name, opposite direction — it's inbound MCP-server auth, not outbound provider OAuth | ADR-006 |
-| Global cross-tenant `videos`/`transcripts` table (dedup) | Reintroduces the cross-domain DB coupling the homelab review is removing; at 1–5 users, re-summarizing is cheaper than the coupling | data-model.md |
+| Global cross-tenant `videos`/`transcripts` table (dedup) | Reintroduces the cross-domain DB coupling the homelab review is removing; at 1–5 users, re-summarizing is cheaper than the coupling. **Transcripts half reopened by ADR-021** — the avoided cost there is a rate-gated, reputation-risky *caption fetch*, not LLM re-summarization, so it outweighs the coupling; **videos stay per-user.** | data-model.md, **ADR-021** (transcripts only) |
 | Audio-download + Whisper STT in the core path | ToS-grey, breakage-prone (yt-dlp), contends for koala GPU with the JEPA PoC; captions alone test the core hypothesis | ADR-007 |
 | Building multi-tenant SaaS / Google OAuth verification now | "Real users soon" was lowered to Future B; SaaS machinery before the Stage 0 self-use gate is the primary documented anti-goal | ADR-008, VISION |
 | Delegating the S5 reuse spike to an agent swarm | A 1-hour sequential read-and-judge with a single coupled conclusion; orchestration overhead exceeds the work, and it's Diamond-1 judgment the maintainer wanted to own | (process note) |

cmd/tapir/processor.go

@@ -3,6 +3,7 @@ package main
 import (
 	"context"
 	"fmt"
+	"strings"
 
 	"gitea.d-ma.be/mathias/tapir/internal/adapters/llm"
 	"gitea.d-ma.be/mathias/tapir/internal/adapters/secrets"
@@ -42,6 +43,40 @@ func (f videoFetcher) FetchVideo(ctx context.Context, userID, videoID string) (d
 // queue-only fallback: the web UI keeps working (the button just queues) and
 // `tapir run` reports the gap via its own ValidateForRun. Missing engine config
 // is never an error here.
+// buildSummarizer wires the summarization endpoint chain (ADR-022) shared by the
+// web "Summarize now" path and the scheduler's per-user runners. The chain is:
+// primary (local, fast) → local fallback → cloud fallback (worst case). Each
+// endpoint reaches the same LiteLLM gateway with a different model alias — the
+// gateway fronts both llama-swap and berget — so a fallback is just a different
+// alias, not a second client config. Empty model entries are skipped, so a
+// client deployment can set the cloud fallback empty to keep content local.
+func buildSummarizer(cfg config.Config) *summarizer.Summarizer {
+	mk := func(model string) summarizer.Endpoint {
+		return summarizer.Endpoint{
+			Client:   llm.New(cfg.GatewayURL, cfg.GatewayKey, model, cfg.SummarizerTimeout, llm.WithMaxTokens(cfg.SummaryMaxTokens)),
+			Provider: providerOf(model),
+			Model:    model,
+		}
+	}
+	eps := []summarizer.Endpoint{mk(cfg.SummarizerModel)}
+	if cfg.FallbackModel != "" && cfg.FallbackModel != cfg.SummarizerModel {
+		eps = append(eps, mk(cfg.FallbackModel))
+	}
+	if cfg.CloudFallbackModel != "" && cfg.CloudFallbackModel != cfg.SummarizerModel {
+		eps = append(eps, mk(cfg.CloudFallbackModel))
+	}
+	return summarizer.NewChain(eps, cfg.MaxTranscriptChars)
+}
+
+// providerOf maps a model alias to the domain AIProvider recorded on summaries.
+// A "berget/" alias is an external provider; everything else is the local stack.
+func providerOf(model string) string {
+	if strings.HasPrefix(model, "berget/") {
+		return "berget"
+	}
+	return "local"
+}
+
 func buildProcessor(cfg config.Config, st *store.Store) (*usecase.Engine, error) {
 	if cfg.GatewayURL == "" || cfg.YTClientID == "" || cfg.YTClientSecret == "" || cfg.SecretsFile == "" {
 		return nil, nil
@@ -55,15 +90,14 @@ func buildProcessor(cfg config.Config, st *store.Store) (*usecase.Engine, error)
 		PreferredLanguages: []string{"en"},
 	}, secretStore)
 
-	// Local Primary only; no BYO fallback for the demo (fallback nil).
+	sum := buildSummarizer(cfg)
-	primary := summarizer.Endpoint{
-		Client:   llm.New(cfg.GatewayURL, cfg.GatewayKey, cfg.SummarizerModel, cfg.SummarizerTimeout),
-		Provider: "local",
-		Model:    cfg.SummarizerModel,
-	}
-	sum := summarizer.New(primary, nil)
 
-	return usecase.NewEngine(src, sum, st), nil
+	// The store is both the summary sink and the shared transcript cache (ADR-021):
+	// the engine reads stored transcripts before any caption fetch and writes
+	// resolved ones back, so re-analysis never re-touches YouTube.
+	eng := usecase.NewEngine(src, sum, st)
+	eng.Transcripts = st
+	return eng, nil
 }
 
 // engineProcessor adapts the engine (which works in terms of a domain.Video) to

cmd/tapir/scheduler.go

@@ -6,9 +6,7 @@ import (
 	"log/slog"
 	"time"
 
-	"gitea.d-ma.be/mathias/tapir/internal/adapters/llm"
 	"gitea.d-ma.be/mathias/tapir/internal/adapters/store"
-	"gitea.d-ma.be/mathias/tapir/internal/adapters/summarizer"
 	"gitea.d-ma.be/mathias/tapir/internal/adapters/youtube"
 	"gitea.d-ma.be/mathias/tapir/internal/config"
 	"gitea.d-ma.be/mathias/tapir/internal/ports"
@@ -37,12 +35,12 @@ func buildUserRunner(cfg config.Config, st *store.Store, secretStore ports.Secre
 		PreferredLanguages: []string{"en"},
 	}, secretStore)
 
-	primary := summarizer.Endpoint{
+	engine := usecase.NewEngine(src, buildSummarizer(cfg), st)
-		Client:   llm.New(cfg.GatewayURL, cfg.GatewayKey, cfg.SummarizerModel, cfg.SummarizerTimeout),
+	// Share the transcript cache (ADR-021) on the scheduler path too — without
-		Provider: "local",
+	// this every scheduled pass re-fetches transcripts it already had, burning the
-		Model:    cfg.SummarizerModel,
+	// scarce per-IP caption budget (ADR-014) and starving other users. The web
-	}
+	// "Summarize now" path already sets this; the scheduler omitting it was a bug.
-	engine := usecase.NewEngine(src, summarizer.New(primary, nil), st)
+	engine.Transcripts = st
 
 	return runner.New(src, st, engine, userID, log,
 		runner.WithBackoff(cfg.FetchBackoff),
@@ -64,6 +62,7 @@ type userLister interface {
 // isolation). Returns the stats summed across users.
 func runDiscoveryPass(
 	ctx context.Context,
+	pass int,
 	lister userLister,
 	runUser func(context.Context, string) (runner.Stats, error),
 	log *slog.Logger,
@@ -74,6 +73,13 @@ func runDiscoveryPass(
 		return runner.Stats{}
 	}
 
+	// Rotate who goes first each pass. Caption fetches share one per-egress-IP
+	// rate budget (ADR-014); whoever runs first each pass spends the pre-throttle
+	// window, so a FIXED user order permanently starves whoever is last (a new
+	// pilot user got 0 fetches for 12h while the first-listed user got all of
+	// them). Rotation gives every user the lead slot in turn.
+	users = rotateUsers(users, pass)
+
 	log.Info("scheduler: starting discovery pass", "users", len(users))
 	var total runner.Stats
 	for _, u := range users {
@@ -123,7 +129,8 @@ func runScheduler(
 		return // disabled
 	}
 
-	runDiscoveryPass(ctx, lister, runUser, log)
+	pass := 0
+	runDiscoveryPass(ctx, pass, lister, runUser, log)
 
 	ticker := time.NewTicker(interval)
 	defer ticker.Stop()
@@ -132,11 +139,32 @@ func runScheduler(
 		case <-ctx.Done():
 			return
 		case <-ticker.C:
-			runDiscoveryPass(ctx, lister, runUser, log)
+			pass++
+			runDiscoveryPass(ctx, pass, lister, runUser, log)
 		}
 	}
 }
 
+// rotateUsers left-rotates users by pass positions so a different user leads each
+// pass. With n users, user i leads on every pass where pass ≡ i (mod n). A pass
+// offset that is negative or exceeds n is normalised. Order within the rotation
+// is otherwise preserved, so the set of users run is unchanged — only who is
+// first (and thus wins the scarce caption-fetch budget) rotates.
+func rotateUsers(users []store.UserIdentity, pass int) []store.UserIdentity {
+	n := len(users)
+	if n <= 1 {
+		return users
+	}
+	off := ((pass % n) + n) % n
+	if off == 0 {
+		return users
+	}
+	out := make([]store.UserIdentity, 0, n)
+	out = append(out, users[off:]...)
+	out = append(out, users[:off]...)
+	return out
+}
+
 // sumStats adds two passes' stats field-wise, so runDiscoveryPass can report a
 // per-tick aggregate across all users.
 func sumStats(a, b runner.Stats) runner.Stats {

cmd/tapir/scheduler_test.go

@@ -45,6 +45,7 @@ func (f fakeLister) ConnectionsForUser(_ context.Context, userID string) ([]stor
 type countingRunUser struct {
 	mu      sync.Mutex
 	calls   map[string]int
+	order   []string // userIDs in the order they were run, across all passes
 	failFor map[string]bool
 }
 
@@ -60,12 +61,19 @@ func (c *countingRunUser) run(_ context.Context, userID string) (runner.Stats, e
 	c.mu.Lock()
 	defer c.mu.Unlock()
 	c.calls[userID]++
+	c.order = append(c.order, userID)
 	if c.failFor[userID] {
 		return runner.Stats{Errors: 1}, errors.New("boom")
 	}
 	return runner.Stats{Summarized: 1}, nil
 }
 
+func (c *countingRunUser) runOrder() []string {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	return append([]string(nil), c.order...)
+}
+
 func (c *countingRunUser) count(userID string) int {
 	c.mu.Lock()
 	defer c.mu.Unlock()
@@ -94,7 +102,7 @@ func TestDiscoveryPassRunsEveryUserOnce(t *testing.T) {
 	lister := fakeLister{users: usersN("a", "b", "c")}
 	rc := newCountingRunUser()
 
-	stats := runDiscoveryPass(context.Background(), lister, rc.run, quietLog())
+	stats := runDiscoveryPass(context.Background(), 0, lister, rc.run, quietLog())
 
 	require.Equal(t, 1, rc.count("a"))
 	require.Equal(t, 1, rc.count("b"))
@@ -102,13 +110,31 @@ func TestDiscoveryPassRunsEveryUserOnce(t *testing.T) {
 	require.Equal(t, 3, stats.Summarized, "stats are summed across users")
 }
 
+// Caption fetches share one per-IP budget; a fixed user order starves whoever is
+// last. Each pass must rotate which user leads so the lead slot is shared.
+func TestDiscoveryPassRotatesLeadUser(t *testing.T) {
+	lister := fakeLister{users: usersN("a", "b", "c")}
+	rc := newCountingRunUser()
+
+	runDiscoveryPass(context.Background(), 0, lister, rc.run, quietLog())
+	runDiscoveryPass(context.Background(), 1, lister, rc.run, quietLog())
+	runDiscoveryPass(context.Background(), 2, lister, rc.run, quietLog())
+
+	require.Equal(t, []string{"a", "b", "c", "b", "c", "a", "c", "a", "b"}, rc.runOrder(),
+		"each pass left-rotates the user order so every user leads in turn")
+	// Fairness: over a full rotation cycle every user ran the same number of times.
+	require.Equal(t, 3, rc.count("a"))
+	require.Equal(t, 3, rc.count("b"))
+	require.Equal(t, 3, rc.count("c"))
+}
+
 func TestDiscoveryPassSkipsUsersWithoutConnections(t *testing.T) {
 	// b never connected a video source (e.g. a stale Dex-era orphan identity).
 	// It must be skipped silently — not run and logged as a token error every pass.
 	lister := fakeLister{users: usersN("a", "b", "c"), noConn: map[string]bool{"b": true}}
 	rc := newCountingRunUser()
 
-	stats := runDiscoveryPass(context.Background(), lister, rc.run, quietLog())
+	stats := runDiscoveryPass(context.Background(), 0, lister, rc.run, quietLog())
 
 	require.Equal(t, 1, rc.count("a"))
 	require.Equal(t, 0, rc.count("b"), "a user with no connection must be skipped, not run")
@@ -121,7 +147,7 @@ func TestDiscoveryPassOneUserFailureDoesNotStopOthers(t *testing.T) {
 	lister := fakeLister{users: usersN("a", "b", "c")}
 	rc := newCountingRunUser("b") // user b's pass errors
 
-	stats := runDiscoveryPass(context.Background(), lister, rc.run, quietLog())
+	stats := runDiscoveryPass(context.Background(), 0, lister, rc.run, quietLog())
 
 	require.Equal(t, 1, rc.count("a"))
 	require.Equal(t, 1, rc.count("b"))
@@ -134,7 +160,7 @@ func TestDiscoveryPassListerErrorIsContained(t *testing.T) {
 	lister := fakeLister{err: errors.New("db down")}
 	rc := newCountingRunUser()
 
-	stats := runDiscoveryPass(context.Background(), lister, rc.run, quietLog())
+	stats := runDiscoveryPass(context.Background(), 0, lister, rc.run, quietLog())
 
 	require.Equal(t, 0, rc.total(), "no users enumerated → no passes")
 	require.Equal(t, runner.Stats{}, stats)

docs/data-model.md

@@ -10,12 +10,15 @@ only opaque references to them; the secret material lives in ESO/1Password (ADR-
 
 ## Design decisions baked into this model
 
-- **Per-user isolation, not a shared global video table.** The earlier draft proposed a
+- **Per-user isolation for everything except transcripts.** The earlier draft proposed a
-  global `videos`/`transcripts` table deduped across tenants. Rejected for Future B: it
+  global `videos`/`transcripts` table deduped across tenants. **Videos** stay per-user and
-  reintroduces exactly the cross-domain coupling the homelab architecture review is
+  RLS-scoped — a shared video table reintroduces exactly the cross-domain coupling the homelab
-  removing, and at 1–5 users the cost of occasionally re-summarizing the same video is
+  architecture review is removing. **Transcripts**, however, are now shared (ADR-021): keyed by
-  trivial compared to the isolation it would cost. Each user's data is self-contained.
+  `(provider, provider_video_id)`, no `user_id`, **not** RLS-scoped. The cost avoided there is
-  (Revisit only if Future C makes GPU/transcription cost dominate — a new ADR, not a default.)
+  not LLM re-summarization but a rate-gated, reputation-risky caption fetch (ADR-010/014), which
+  is paid per re-fetch regardless of user count — so persisting public caption content once and
+  sharing it strictly beats the coupling it removes. Everything else each user owns is
+  self-contained; `rls_test.go` proves transcripts is the single exception.
 - **Secrets by reference only.** Tables hold a `secret_ref` (opaque string/UUID resolved via
   the `SecretStore` port), never tokens or keys.
 - **The brain sink is just a delivery target.** No brain-specific tables. Whether a summary
@@ -34,7 +37,7 @@ erDiagram
     USER ||--o{ AI_CREDENTIAL : "has (planned)"
     VIDEO_CONNECTION ||--o{ SUBSCRIPTION : "exposes (planned)"
     SUBSCRIPTION ||--o{ VIDEO : "produces (per user)"
-    VIDEO ||--o| TRANSCRIPT : "has at most one"
+    VIDEO }o--o| TRANSCRIPT : "shares one by (provider, provider_video_id) — not FK (ADR-021)"
     VIDEO ||--o| SUMMARY : "has at most one"
     SUMMARY ||--o{ SINK_DELIVERY : "delivered via"
     USER ||--o{ CHANNEL_ERROR : "reports unavailable channels"
@@ -92,12 +95,12 @@ erDiagram
         timestamptz rate_limited_at "backoff clock for 429 retries (migration 007)"
     }
     TRANSCRIPT {
-        uuid video_id PK_FK
+        text provider PK "part of shared key (ADR-021)"
-        uuid user_id FK
+        text provider_video_id PK "part of shared key — the cross-user dedup key"
         text source "captions | none"
         text language
         text content "null when source = none"
-        timestamptz resolved_at
+        timestamptz fetched_at
     }
     SUMMARY {
         uuid id PK
@@ -173,8 +176,12 @@ mechanism.
   `transcript_status` and `rate_limited_at` (migration 007) track caption-fetch outcomes for
   rate-limit backoff: `NULL` = not attempted; `rate_limited` = 429 seen, skip until
   `NOW() - rate_limited_at > TAPIR_FETCH_BACKOFF`; `fetched` = resolved; `none` = no transcript.
-- **TRANSCRIPT** — at most one per video. `source = none` records "checked, no usable
+- **TRANSCRIPT** — shared public caption content, one row per `(provider, provider_video_id)`,
-  transcript" so the watcher doesn't reprocess (ADR-007). `content` null in that case.
+  **not** RLS-scoped and carrying no `user_id` (ADR-021). Two users who watch the same video
+  share the one row; the summarize path reads it before any caption fetch, so re-analysis never
+  re-touches YouTube (ADR-010/014). `source = none` records "checked, no usable transcript" so
+  no one reprocesses (ADR-007); `content` null in that case. A transient 429 is never stored
+  here — it stays a per-user retry via `VIDEO.transcript_status`.
 - **SUMMARY** — at most one per video. `fallback_used` + `ai_provider`/`ai_model` make the
   "is local good enough?" question queryable (the Stage 0 quality signal). `highlights`/
   `takeaways` as jsonb to stay schema-flexible while the output format settles.
@@ -231,7 +238,8 @@ queue, doesn't replace it). Deferred until there's a reason.
 
 ## Explicitly out of scope (Future C)
 
-- Global cross-tenant video/transcript dedup (rejected above).
+- Global cross-tenant *video* dedup (rejected above). Note: cross-tenant *transcript* sharing
+  is now in scope and shipped (ADR-021); only the videos half stays per-user.
 - Sharding / per-tenant physical databases.
 - Soft-delete + full audit trail on connections/credentials (a Stage 2 hardening item; add
   via ADR when Stage 2 work starts).

docs/homelab-integration.md

@@ -27,6 +27,18 @@ it** — endpoints and aliases drift, and this file is a snapshot (2026-06-06),
   `iguana/deepseek-r1-14b`) is preferred for summary quality if its latency/output is acceptable.
   The `max_tokens` fix below means thinking models no longer return empty content, so they are now
   viable choices, not blocked ones. Do not assume a coder alias is right for prose.
+- **Summarizer fallback chain (ADR-022).** The primary alias is the *first* of an ordered chain;
+  on failure or unparseable output the summarizer advances to the next model. All reached through
+  the same gateway by alias.
+  - `TAPIR_FALLBACK_MODEL` — local fallback. **Default `koala/phi4-14b`.** Empty disables it.
+  - `TAPIR_CLOUD_FALLBACK_MODEL` — worst-case EXTERNAL fallback. **Default `berget/mistral-small`.**
+    **Set this empty (`""`) for any client/NDA deployment** so content never leaves the local
+    stack — the chain then contains only local endpoints.
+  - `TAPIR_SUMMARY_MAX_TOKENS` — per-summary completion budget. **Default `1500`.** Small on
+    purpose: with the old 8192 budget, prompt + completion overflowed `phi4-mini`'s 8k window.
+  - `TAPIR_MAX_TRANSCRIPT_CHARS` — transcript truncation budget sent to the model. **Default
+    `18000`** (~fits an 8k-context model). `0` disables truncation. Prevents the context-overflow
+    HTTP 400 a long transcript caused on `phi4-mini`.
 - **Thinking models need an explicit `max_tokens`.** qwen3 / deepseek-r1 spend the budget on
   reasoning and return **empty content** if `max_tokens` is too low (or unset). The summarizer's
   parser treats an empty summary as an error for exactly this reason. **Done (2026-06-02, Worker F):**

docs/use-cases/ai_routing.feature

@@ -31,5 +31,17 @@ Feature: Local-first AI with optional BYO fallback
     When any transcript is summarized
     Then my content is only ever sent to the local AI stack
 
-  # "Reliably" is operationalized as: Primary returned without error within timeout.
+  Scenario: A model returns unparseable output and the next endpoint succeeds
+    Given the local AI stack is available
+    But the primary model returns output that cannot be parsed into a summary
+    And a fallback model is configured
+    When a transcript is summarized
+    Then Tapir falls back to the next model in the chain
+    And the summary records fallback_used as true
+
+  # "Reliably" is operationalized as: an endpoint returned a PARSEABLE summary
+  # within timeout. A 200 with malformed JSON (or highlights emitted as a bare
+  # string) counts as a failure and advances the chain (ADR-022). Endpoints are
+  # tried in order, locals first, so the external worst-case model only ever sees
+  # content after every local endpoint has failed.
   # Quality scoring may be added later without changing these scenarios.

docs/use-cases/connect_account.feature

@@ -24,6 +24,12 @@ Feature: Connect and manage video accounts
     Then a discovery pass for my account is triggered right away
     And I do not have to wait for the next scheduled pass to see my videos
 
+  Scenario: Connecting summarizes my newest videos right away
+    Given I have no connected video accounts
+    When I connect my YouTube account
+    Then up to the onboarding cap of my newest videos are summarized through the rate gate
+    And the rest are left to the scheduled recency-bounded pass
+
   Scenario: Tokens are never stored in the clear
     When I connect any video account
     Then no OAuth token value is stored in the database

docs/use-cases/paste_url.feature

@@ -0,0 +1,30 @@
+Feature: Paste a YouTube URL to summarize any video
+  As a user
+  I want to paste a YouTube link and get a summary
+  So that I can pull the specific video I want now, even from channels I don't follow
+
+  Scenario: Paste a valid YouTube URL
+    Given I am connected
+    When I paste a valid YouTube video URL
+    Then the video is added to my feed scoped to me
+    And it is queued for summarization through the shared rate gate
+
+  Scenario: Pasting an invalid link is rejected
+    When I paste something that is not a YouTube video URL
+    Then I get a clear error and nothing is added
+
+  Scenario: Pasting a video that cannot be found is honest
+    When I paste a URL whose video cannot be found
+    Then I am told it couldn't be found and nothing is added
+
+  Scenario: Pasting the same video twice does not duplicate it
+    Given I have pasted a video
+    When I paste the same video again
+    Then my feed still has exactly one entry for it
+
+  @pending
+  # Covered by the engine's ADR-010 no-transcript terminal state (degrade-never-error);
+  # there is no paste-specific test for it.
+  Scenario: A pasted video with no captions resolves honestly
+    When I paste a video that has no captions
+    Then it resolves to the "no transcript available" terminal state

docs/use-cases/summarize_new_video.feature

@@ -31,5 +31,16 @@ Feature: Summarize new videos from subscribed channels
     When the watcher sees "Designing for Attention" again
     Then Tapir does not produce a second summary for it
 
+  Scenario: Re-analyzing a stored video does not re-fetch its transcript
+    Given a transcript for "Designing for Attention" is already stored
+    When the video is summarized again
+    Then Tapir reads the stored transcript
+    And Tapir does not fetch captions from YouTube
+
   # Captions-first is the core path (ADR-007). Audio-download + speech-to-text is
   # deferred and intentionally has no scenario here yet.
+  #
+  # Transcript persistence (ADR-021): the stored transcript is shared, keyed by
+  # (provider, provider_video_id) and read before any caption fetch, so the
+  # re-analysis scenario above also covers paste-a-URL and the onboarding burst —
+  # both summarize through the same engine chokepoint.

internal/adapters/llm/client.go

@@ -34,15 +34,35 @@ type Client struct {
 	httpClient *http.Client
 }
 
+// Option configures a Client at construction. Variadic so the existing 4-arg
+// call sites stay valid as new knobs are added.
+type Option func(*Client)
+
+// WithMaxTokens overrides the per-request completion budget. The summarizer uses
+// this to cap completion for small-context models (e.g. koala/phi4-mini, 8k):
+// with the default 8192 budget, prompt + max_tokens overflows an 8k context and
+// the gateway returns HTTP 400. A non-positive n is ignored (keeps the default).
+func WithMaxTokens(n int) Option {
+	return func(c *Client) {
+		if n > 0 {
+			c.maxTokens = n
+		}
+	}
+}
+
 // New constructs a Client.
-func New(baseURL, apiKey, model string, timeout time.Duration) *Client {
+func New(baseURL, apiKey, model string, timeout time.Duration, opts ...Option) *Client {
-	return &Client{
+	c := &Client{
 		baseURL:    strings.TrimRight(baseURL, "/"),
 		apiKey:     apiKey,
 		model:      model,
 		maxTokens:  defaultMaxTokens,
 		httpClient: &http.Client{Timeout: timeout},
 	}
+	for _, opt := range opts {
+		opt(c)
+	}
+	return c
 }
 
 type chatRequest struct {

internal/adapters/llm/client_test.go

@@ -64,6 +64,27 @@ func TestClient_SendsMaxTokens(t *testing.T) {
 	}
 }
 
+// TestClient_WithMaxTokens overrides the completion budget — the summarizer caps
+// it small so prompt + max_tokens fits a small-context model's window (8k).
+func TestClient_WithMaxTokens(t *testing.T) {
+	var body chatRequest
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		_ = json.NewDecoder(r.Body).Decode(&body)
+		_ = json.NewEncoder(w).Encode(map[string]any{
+			"choices": []map[string]any{{"message": map[string]any{"content": "ok"}}},
+		})
+	}))
+	defer srv.Close()
+
+	c := New(srv.URL, "", "test-model", 10*time.Second, WithMaxTokens(1500))
+	if _, err := c.Complete(context.Background(), "sys", "user"); err != nil {
+		t.Fatalf("Complete: %v", err)
+	}
+	if body.MaxTokens != 1500 {
+		t.Errorf("max_tokens = %d, want 1500", body.MaxTokens)
+	}
+}
+
 func TestClient_ReturnsErrorOnNon200(t *testing.T) {
 	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		http.Error(w, "overloaded", http.StatusServiceUnavailable)

internal/adapters/store/account.go

@@ -10,10 +10,13 @@ import (
 // DeleteUser permanently removes a user and all of their data. It runs through
 // withUser so RLS confines every statement to the calling user's own rows.
 //
-// Deleting the users row cascades (ON DELETE CASCADE) to videos, transcripts,
+// Deleting the users row cascades (ON DELETE CASCADE) to videos, summaries
-// summaries (→ sink_deliveries), video_connections, and the user_identities map
+// (→ sink_deliveries), video_connections, and the user_identities map —
-// — referential-integrity cascades bypass RLS, so a user's child rows are removed
+// referential-integrity cascades bypass RLS, so a user's child rows are removed
-// even though the deleting connection is scoped. summary_actions and login_events
+// even though the deleting connection is scoped. Transcripts are NOT removed:
+// since ADR-021 they are shared public content keyed by (provider,
+// provider_video_id) with no user_id, so another user may still reference the
+// same row — a user deletion must not strip shared caption content. summary_actions and login_events
 // are the exceptions: each carries a user_id but has NO foreign key to users
 // (migrations 002 and 010), so the cascade does not reach them; they are deleted
 // explicitly in the same scoped transaction. Deleting an absent user is a no-op

internal/adapters/store/migrate_test.go

@@ -53,7 +53,11 @@ func TestMigration010LoginEventsUpDown(t *testing.T) {
 	require.True(t, loginEventsExists(t), "login_events must exist at latest migration")
 
 	m := fileMigrator(t)
-	// 011, 012, 013 sit above 010; step them down first so 010 is exercised in isolation.
+	// 011..015 sit above 010; step them down first so 010 is exercised in isolation.
+	require.NoError(t, m.Steps(-1), "down 015 reshapes transcripts, login_events intact")
+	require.True(t, loginEventsExists(t), "015 down leaves login_events intact")
+	require.NoError(t, m.Steps(-1), "down 014 drops channel_title, login_events intact")
+	require.True(t, loginEventsExists(t), "014 down leaves login_events intact")
 	require.NoError(t, m.Steps(-1), "down 013 drops channel_errors, login_events intact")
 	require.True(t, loginEventsExists(t), "013 down leaves login_events intact")
 	require.NoError(t, m.Steps(-1), "down 012 is a no-op, login_events intact")
@@ -64,7 +68,7 @@ func TestMigration010LoginEventsUpDown(t *testing.T) {
 	require.NoError(t, m.Steps(-1), "down 010 must drop login_events")
 	require.False(t, loginEventsExists(t), "login_events must be gone after the down migration")
 
-	require.NoError(t, m.Steps(4), "up must recreate 010 then re-apply 011, 012, 013")
+	require.NoError(t, m.Steps(6), "up must recreate 010 then re-apply 011..015")
 	require.True(t, loginEventsExists(t), "login_events must be restored after the up migration")
 }
 
@@ -87,6 +91,8 @@ func TestMigration011AutoSummarizeDefaultUpDown(t *testing.T) {
 	require.Equal(t, "true", autoSummarizeDefault(t), "011 sets the default to TRUE")
 
 	m := fileMigrator(t)
+	require.NoError(t, m.Steps(-1), "down 015 reshapes transcripts")
+	require.NoError(t, m.Steps(-1), "down 014 drops channel_title")
 	require.NoError(t, m.Steps(-1), "down 013 drops channel_errors")
 	require.NoError(t, m.Steps(-1), "down 012 is a no-op")
 	require.NoError(t, m.Steps(-1), "down 011 reverts the column default")
@@ -96,6 +102,35 @@ func TestMigration011AutoSummarizeDefaultUpDown(t *testing.T) {
 	require.Equal(t, "true", autoSummarizeDefault(t))
 	require.NoError(t, m.Steps(1), "up 012 runs clean (no FORCE RLS on fresh schema)")
 	require.NoError(t, m.Steps(1), "up 013 creates channel_errors")
+	require.NoError(t, m.Steps(1), "up 014 recreates channel_title")
+	require.NoError(t, m.Steps(1), "up 015 reshapes transcripts to shared")
+}
+
+// channelTitleExists reports whether videos.channel_title is present.
+func channelTitleExists(t *testing.T) bool {
+	t.Helper()
+	var exists bool
+	require.NoError(t, rawPool(t).QueryRow(context.Background(),
+		`SELECT EXISTS (SELECT 1 FROM information_schema.columns
+		  WHERE table_name = 'videos' AND column_name = 'channel_title')`).Scan(&exists))
+	return exists
+}
+
+// TestMigration014VideoChannelTitleUpDown proves 014 is reversible: down drops
+// videos.channel_title, up recreates it.
+func TestMigration014VideoChannelTitleUpDown(t *testing.T) {
+	newStore(t) // latest (014 applied)
+	require.True(t, channelTitleExists(t), "channel_title exists at latest migration")
+
+	m := fileMigrator(t)
+	require.NoError(t, m.Steps(-1), "down 015 reshapes transcripts, channel_title intact")
+	require.True(t, channelTitleExists(t), "015 down leaves channel_title intact")
+	require.NoError(t, m.Steps(-1), "down 014 must drop channel_title")
+	require.False(t, channelTitleExists(t), "channel_title must be gone after the down migration")
+
+	require.NoError(t, m.Steps(1), "up 014 must recreate channel_title")
+	require.True(t, channelTitleExists(t), "channel_title must be restored after the up migration")
+	require.NoError(t, m.Steps(1), "up 015 restores the shared transcripts shape (HEAD)")
 }
 
 // TestMigration012FixAutoSummarizeRLS proves 012 runs cleanly and flips any

internal/adapters/store/migrations/014_video_channel_title.down.sql

@@ -0,0 +1 @@
+ALTER TABLE videos DROP COLUMN channel_title;

internal/adapters/store/migrations/014_video_channel_title.up.sql

@@ -0,0 +1,8 @@
+-- Store the source channel's title per video so the list can offer a real
+-- channel filter (multi-select of the user's channels) instead of the dead
+-- free-text field that only ever matched the provider string. Nullable: existing
+-- rows backfill on the next discovery pass (UpsertVideo writes it); pasted videos
+-- get it immediately from videos.list. No FK to a channels table at Stage 0 — the
+-- title is a denormalised display/filter value, consistent with the existing
+-- subscription_id-stays-NULL stance (data-model.md).
+ALTER TABLE videos ADD COLUMN channel_title TEXT;

internal/adapters/store/migrations/015_shared_transcripts.down.sql

@@ -0,0 +1,19 @@
+-- Down 015: restore the per-user RLS-scoped transcripts shape (001 + 003).
+DROP TABLE transcripts;
+
+CREATE TABLE transcripts (
+    video_id    UUID PRIMARY KEY REFERENCES videos(id) ON DELETE CASCADE,
+    user_id     UUID NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    source      TEXT NOT NULL,
+    language    TEXT,
+    content     TEXT,
+    resolved_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+CREATE INDEX idx_transcripts_user_id ON transcripts(user_id);
+
+ALTER TABLE transcripts ENABLE ROW LEVEL SECURITY;
+ALTER TABLE transcripts FORCE ROW LEVEL SECURITY;
+CREATE POLICY transcripts_isolation ON transcripts
+    FOR ALL
+    USING (user_id = current_setting('tapir.current_user_id', true)::uuid);

internal/adapters/store/migrations/015_shared_transcripts.up.sql

@@ -0,0 +1,30 @@
+-- Migration 015: transcripts become SHARED public-content storage (ADR-021).
+--
+-- The per-user transcripts table from 001 (PK videos.id, user_id NOT NULL, RLS
+-- FORCEd in 003) was dead: no application code ever read or wrote it — only the
+-- transcript_status columns on `videos` (007) carried fetch outcomes. ADR-021
+-- repurposes it as the single shared store of public caption content, keyed by
+-- the cross-user dedup key (provider, provider_video_id) — the video's public
+-- identity, not Tapir's per-user videos.id — so re-analysis never re-fetches
+-- from YouTube (ADR-010/014).
+--
+-- It holds ONLY public caption content + the video's public id (nothing
+-- user-identifying), so it is deliberately NOT RLS-scoped: no user_id, no
+-- policy, no FORCE. This is the single, intentional exception to the ADR-012
+-- isolation boundary; rls_test.go asserts the boundary is exactly here and
+-- nowhere else. Dropping the old table drops its RLS policy with it; it held no
+-- real data, so drop+recreate loses nothing.
+DROP TABLE transcripts;
+
+CREATE TABLE transcripts (
+    provider          TEXT NOT NULL,
+    provider_video_id TEXT NOT NULL,
+    source            TEXT NOT NULL, -- 'captions' (content set) | 'none' (no captions; content NULL)
+    language          TEXT,
+    content           TEXT,
+    fetched_at        TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    PRIMARY KEY (provider, provider_video_id)
+);
+
+COMMENT ON TABLE transcripts IS
+    'Shared public caption content keyed by (provider, provider_video_id). NOT RLS-scoped — public content only, de-facto cross-user dedup (ADR-021).';

internal/adapters/store/reads.go

@@ -29,6 +29,7 @@ type SummaryRow struct {
 	ProviderVideoID string    // videos.provider_video_id; empty when no videos row
 	Title           string    // videos.title; empty when no videos row
 	Channel         string    // videos.provider for now; empty when no videos row
+	ChannelTitle    string    // videos.channel_title; the source channel, for display + filtering
 	URL             string    // videos.url; empty when no videos row
 	PublishedAt     time.Time // videos.published_at; zero when absent
 	Summary         string
@@ -137,7 +138,8 @@ const selectVideo = `
 	       COALESCE(s.created_at, v.seen_at),
 	       (s.id IS NOT NULL) AS summarized,
 	       v.summarize_requested,
-	       COALESCE(v.transcript_status, '')
+	       COALESCE(v.transcript_status, ''),
+	       COALESCE(v.channel_title, '')
 	  FROM videos v
 	  LEFT JOIN summaries s ON s.video_id = v.id AND s.user_id = v.user_id`
 
@@ -254,6 +256,7 @@ func scanVideoRow(rows pgx.Row) (SummaryRow, error) {
 		&row.Summarized,
 		&row.SummarizeRequested,
 		&row.TranscriptStatus,
+		&row.ChannelTitle,
 	); err != nil {
 		return SummaryRow{}, fmt.Errorf("store: scan video: %w", err)
 	}

internal/adapters/store/rls_test.go

@@ -22,9 +22,11 @@ import (
 // (no GUC set → zero rows) proves the enforcement path is live, not bypassed.
 
 // userIsolatedTables are the tables that carry a user_id and whose policy keys
-// directly off the tapir.current_user_id GUC.
+// directly off the tapir.current_user_id GUC. transcripts is deliberately ABSENT
+// — ADR-021 made it shared public content (non-RLS); TestTranscriptsTableIsSharedNotRLS
+// proves that is the only place the isolation boundary moved.
 var userIsolatedTables = []string{
-	"users", "videos", "transcripts", "summaries", "summary_actions", "login_events", "video_connections",
+	"users", "videos", "summaries", "summary_actions", "login_events", "video_connections",
 }
 
 // allIsolatedTables adds sink_deliveries, whose ownership is derived from its
@@ -38,9 +40,10 @@ type seeded struct {
 	summaryID string
 }
 
-// seedUser inserts one full chain (user → video → transcript → summary →
+// seedUser inserts one full chain (user → video → summary → action → delivery)
-// action → delivery) as the superuser pool, which bypasses RLS so both users'
+// as the superuser pool, which bypasses RLS so both users' data lands regardless
-// data lands regardless of the GUC.
+// of the GUC. Transcripts are NOT seeded here: they are shared, non-RLS public
+// content (ADR-021), so they have no place in a per-user isolation chain.
 func seedUser(t *testing.T, p *pgxpool.Pool, userID string) seeded {
 	t.Helper()
 	ctx := context.Background()
@@ -54,11 +57,6 @@ func seedUser(t *testing.T, p *pgxpool.Pool, userID string) seeded {
 		 VALUES ($1, 'youtube', $2, 'title') RETURNING id`,
 		userID, "vid-"+userID).Scan(&videoID))
 
-	_, err = p.Exec(ctx,
-		`INSERT INTO transcripts (video_id, user_id, source, content)
-		 VALUES ($1, $2, 'captions', 'words')`, videoID, userID)
-	require.NoError(t, err)
-
 	var summaryID string
 	require.NoError(t, p.QueryRow(ctx,
 		`INSERT INTO summaries (user_id, video_id, summary) VALUES ($1, $2, 'sum')
@@ -92,9 +90,16 @@ func appPool(t *testing.T, super *pgxpool.Pool) *pgxpool.Pool {
 	t.Helper()
 	ctx := context.Background()
 
-	// Idempotent across test runs (schema/role persist for the TestMain PG).
+	// Idempotent across tests AND runs: the role persists for the TestMain PG and
-	_, _ = super.Exec(ctx, `DROP ROLE IF EXISTS app`)
+	// owns granted privileges, so a plain DROP ROLE fails once any GRANT exists
-	_, err := super.Exec(ctx, `CREATE ROLE app LOGIN PASSWORD 'app'`)
+	// (and more than one test now builds an app pool). Create only if absent; the
+	// GRANTs below are themselves idempotent.
+	_, err := super.Exec(ctx,
+		`DO $$ BEGIN
+		    IF NOT EXISTS (SELECT FROM pg_roles WHERE rolname = 'app') THEN
+		        CREATE ROLE app LOGIN PASSWORD 'app';
+		    END IF;
+		 END $$`)
 	require.NoError(t, err)
 	_, err = super.Exec(ctx, `GRANT USAGE ON SCHEMA public TO app`)
 	require.NoError(t, err)
@@ -186,7 +191,6 @@ func TestRLSEnforcesPerUserIsolation(t *testing.T) {
 		{"update users", `UPDATE users SET display_name = 'hacked' WHERE id = $1`, b.userID},
 		{"update videos", `UPDATE videos SET title = 'hacked' WHERE user_id = $1`, b.userID},
 		{"queue videos summarize", `UPDATE videos SET summarize_requested = TRUE WHERE id = $1`, b.videoID},
-		{"update transcripts", `UPDATE transcripts SET content = 'hacked' WHERE user_id = $1`, b.userID},
 		{"update summaries", `UPDATE summaries SET summary = 'hacked' WHERE user_id = $1`, b.userID},
 		{"update summary_actions", `UPDATE summary_actions SET action = 'skipped' WHERE user_id = $1`, b.userID},
 		{"update login_events", `UPDATE login_events SET seen_at = NOW() WHERE user_id = $1`, b.userID},
@@ -235,3 +239,55 @@ func TestRLSEnforcesPerUserIsolation(t *testing.T) {
 
 	_ = a // a's ids are seeded for the symmetric read assertions above
 }
+
+// TestTranscriptsTableIsSharedNotRLS is the ADR-021 isolation proof: transcripts
+// is the ONE shared, non-RLS surface, and the public-content classification
+// leaked to nothing else. It is the inverse of TestRLSEnforcesPerUserIsolation —
+// where that asserts deny-all on every user-owned table, this asserts transcripts
+// is readable and writable with no user scope at all, holds no user_id, and is
+// the single table with row-level security switched off.
+func TestTranscriptsTableIsSharedNotRLS(t *testing.T) {
+	newStore(t)
+	super := rawPool(t)
+	resetDB(t, super)
+	app := appPool(t, super)
+	ctx := context.Background()
+
+	// 1. Shared + non-RLS: with NO GUC set, the app role both writes and reads a
+	//    transcript. On an RLS table this would be deny-all (zero rows), exactly as
+	//    the main isolation test asserts for every user-owned table.
+	_, err := app.Exec(ctx,
+		`INSERT INTO transcripts (provider, provider_video_id, source, content)
+		 VALUES ('youtube', 'shared-vid', 'captions', 'public words')`)
+	require.NoError(t, err, "app role must write shared transcript content with no user scope")
+	require.Equal(t, 1, scopedCount(t, app, "", "transcripts"),
+		"transcripts must be readable with NO user scope — it is shared, non-RLS (ADR-021)")
+
+	// 2. No user_id column: the table holds only public caption content + the
+	//    video's public id, nothing user-identifying.
+	var hasUserID bool
+	require.NoError(t, super.QueryRow(ctx,
+		`SELECT EXISTS (SELECT 1 FROM information_schema.columns
+		                 WHERE table_name = 'transcripts' AND column_name = 'user_id')`).Scan(&hasUserID))
+	require.False(t, hasUserID, "transcripts must carry no user_id (ADR-021 public content)")
+
+	// 3. The boundary is EXACTLY here: every user-owned table still has row-level
+	//    security enabled; transcripts alone has it off. This is the proof the
+	//    non-RLS classification was applied to transcripts and leaked nowhere else.
+	for _, table := range allIsolatedTables {
+		require.True(t, rlsEnabled(t, super, table),
+			"%s must still enforce row-level security — isolation must not have regressed", table)
+	}
+	require.False(t, rlsEnabled(t, super, "transcripts"),
+		"transcripts must be the single table with row-level security OFF (the one shared surface)")
+}
+
+// rlsEnabled reports whether a public table has ROW LEVEL SECURITY enabled.
+func rlsEnabled(t *testing.T, p *pgxpool.Pool, table string) bool {
+	t.Helper()
+	var enabled bool
+	require.NoError(t, p.QueryRow(context.Background(),
+		`SELECT relrowsecurity FROM pg_class
+		  WHERE relname = $1 AND relnamespace = 'public'::regnamespace`, table).Scan(&enabled))
+	return enabled
+}

internal/adapters/store/transcript.go

@@ -0,0 +1,66 @@
+package store
+
+import (
+	"context"
+	"errors"
+	"fmt"
+
+	"github.com/jackc/pgx/v5"
+
+	"gitea.d-ma.be/mathias/tapir/internal/domain"
+)
+
+// GetTranscript returns the shared, stored transcript for a video keyed by the
+// cross-user dedup key (provider, providerVideoID), and whether one exists
+// (ADR-021). It reads via the raw pool, NOT withUser: the table holds public
+// content with no user_id and no RLS policy, so it is shared across users by
+// construction. A stored SourceNone is a real hit (ok == true, HasText() ==
+// false) — a known caption-less video, so the caller skips without re-fetching.
+func (s *Store) GetTranscript(ctx context.Context, provider, providerVideoID string) (domain.Transcript, bool, error) {
+	var source, lang, content string
+	err := s.pool.QueryRow(ctx,
+		`SELECT source, COALESCE(language, ''), COALESCE(content, '')
+		   FROM transcripts WHERE provider = $1 AND provider_video_id = $2`,
+		provider, providerVideoID).Scan(&source, &lang, &content)
+	if errors.Is(err, pgx.ErrNoRows) {
+		return domain.Transcript{}, false, nil
+	}
+	if err != nil {
+		return domain.Transcript{}, false, fmt.Errorf("store: get transcript: %w", err)
+	}
+	return domain.Transcript{
+		Source:   domain.TranscriptSource(source),
+		Language: lang,
+		Content:  content,
+	}, true, nil
+}
+
+// SaveTranscript upserts the shared transcript for (provider, providerVideoID).
+// Only terminal outcomes belong here: SourceCaptions (with text) or SourceNone
+// (no captions). A transient SourceRateLimited is rejected so persistence never
+// masks a 429 as a permanent absence — that stays a per-user retry (ADR-014).
+// Last write wins on conflict (a later re-fetch may correct an entry). It writes
+// via the raw pool, NOT withUser — public content, shared, non-RLS (ADR-021).
+func (s *Store) SaveTranscript(ctx context.Context, provider, providerVideoID string, t domain.Transcript) error {
+	switch t.Source {
+	case domain.SourceCaptions, domain.SourceNone:
+		// terminal — persist
+	case domain.SourceRateLimited:
+		return fmt.Errorf("store: refusing to persist transient rate-limited transcript for %s/%s", provider, providerVideoID)
+	default:
+		return fmt.Errorf("store: invalid transcript source %q", t.Source)
+	}
+	_, err := s.pool.Exec(ctx,
+		`INSERT INTO transcripts (provider, provider_video_id, source, language, content)
+		      VALUES ($1, $2, $3, NULLIF($4, ''), NULLIF($5, ''))
+		 ON CONFLICT (provider, provider_video_id)
+		 DO UPDATE SET source     = EXCLUDED.source,
+		               language   = EXCLUDED.language,
+		               content    = EXCLUDED.content,
+		               fetched_at = NOW()`,
+		provider, providerVideoID, string(t.Source), t.Language, t.Content)
+	if err != nil {
+		return fmt.Errorf("store: save transcript: %w", err)
+	}
+	return nil
+}

internal/adapters/store/transcript_test.go

@@ -0,0 +1,87 @@
+package store_test
+
+import (
+	"context"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"gitea.d-ma.be/mathias/tapir/internal/adapters/store"
+	"gitea.d-ma.be/mathias/tapir/internal/domain"
+	"gitea.d-ma.be/mathias/tapir/internal/ports"
+)
+
+// Static check: Store satisfies the shared TranscriptStore port (ADR-021).
+var _ ports.TranscriptStore = (*store.Store)(nil)
+
+func TestSaveAndGetTranscript_RoundTrip(t *testing.T) {
+	s := newStore(t)
+	resetDB(t, rawPool(t))
+	ctx := context.Background()
+
+	want := domain.Transcript{Source: domain.SourceCaptions, Language: "en", Content: "the words"}
+	require.NoError(t, s.SaveTranscript(ctx, "youtube", "vid-1", want))
+
+	got, ok, err := s.GetTranscript(ctx, "youtube", "vid-1")
+	require.NoError(t, err)
+	require.True(t, ok, "a saved transcript must be found")
+	require.Equal(t, domain.SourceCaptions, got.Source)
+	require.Equal(t, "en", got.Language)
+	require.Equal(t, "the words", got.Content)
+	require.True(t, got.HasText())
+}
+
+func TestGetTranscript_Miss(t *testing.T) {
+	s := newStore(t)
+	resetDB(t, rawPool(t))
+
+	_, ok, err := s.GetTranscript(context.Background(), "youtube", "absent")
+	require.NoError(t, err, "a miss is not an error")
+	require.False(t, ok)
+}
+
+// A stored "no captions" outcome is a real hit: callers must skip without
+// re-fetching, so ok is true even though there is no text (ADR-021 / ADR-007).
+func TestSaveAndGetTranscript_NoneIsAStoredHit(t *testing.T) {
+	s := newStore(t)
+	resetDB(t, rawPool(t))
+	ctx := context.Background()
+
+	require.NoError(t, s.SaveTranscript(ctx, "youtube", "vid-none", domain.Transcript{Source: domain.SourceNone}))
+
+	got, ok, err := s.GetTranscript(ctx, "youtube", "vid-none")
+	require.NoError(t, err)
+	require.True(t, ok, "a stored SourceNone is a hit, not a miss")
+	require.Equal(t, domain.SourceNone, got.Source)
+	require.False(t, got.HasText())
+}
+
+// A transient 429 must never be persisted as a terminal transcript, or a later
+// read would mask the rate-limit as a permanent "no transcript" (ADR-014).
+func TestSaveTranscript_RejectsRateLimited(t *testing.T) {
+	s := newStore(t)
+	resetDB(t, rawPool(t))
+
+	err := s.SaveTranscript(context.Background(), "youtube", "vid-429",
+		domain.Transcript{Source: domain.SourceRateLimited})
+	require.Error(t, err)
+
+	_, ok, _ := s.GetTranscript(context.Background(), "youtube", "vid-429")
+	require.False(t, ok, "a rejected rate-limited save must leave nothing stored")
+}
+
+func TestSaveTranscript_UpsertLastWriteWins(t *testing.T) {
+	s := newStore(t)
+	resetDB(t, rawPool(t))
+	ctx := context.Background()
+
+	require.NoError(t, s.SaveTranscript(ctx, "youtube", "vid-up", domain.Transcript{Source: domain.SourceNone}))
+	require.NoError(t, s.SaveTranscript(ctx, "youtube", "vid-up",
+		domain.Transcript{Source: domain.SourceCaptions, Language: "en", Content: "now resolved"}))
+
+	got, ok, err := s.GetTranscript(ctx, "youtube", "vid-up")
+	require.NoError(t, err)
+	require.True(t, ok)
+	require.Equal(t, domain.SourceCaptions, got.Source)
+	require.Equal(t, "now resolved", got.Content)
+}

internal/adapters/store/videos.go

@@ -46,14 +46,15 @@ func (s *Store) UpsertVideo(ctx context.Context, v domain.Video) (string, error)
 		}
 
 		if err := tx.QueryRow(ctx,
-			`INSERT INTO videos (user_id, provider, provider_video_id, title, url, published_at)
+			`INSERT INTO videos (user_id, provider, provider_video_id, title, url, published_at, channel_title)
-			 VALUES ($1, $2, $3, $4, $5, $6)
+			 VALUES ($1, $2, $3, $4, $5, $6, $7)
 			 ON CONFLICT (user_id, provider, provider_video_id) DO UPDATE SET
-			     title        = EXCLUDED.title,
+			     title         = EXCLUDED.title,
-			     url          = EXCLUDED.url,
+			     url           = EXCLUDED.url,
-			     published_at = EXCLUDED.published_at
+			     published_at  = EXCLUDED.published_at,
+			     channel_title = COALESCE(NULLIF(EXCLUDED.channel_title, ''), videos.channel_title)
 			 RETURNING id`,
-			v.UserID, provider, v.ProviderVideoID, v.Title, v.URL, nullTime(v.PublishedAt),
+			v.UserID, provider, v.ProviderVideoID, v.Title, v.URL, nullTime(v.PublishedAt), v.ChannelTitle,
 		).Scan(&id); err != nil {
 			return fmt.Errorf("store: upsert video: %w", err)
 		}
@@ -110,3 +111,31 @@ func (s *Store) NewestUnsummarizedVideoIDs(ctx context.Context, userID string, l
 	}
 	return ids, nil
 }
+
+// DistinctChannels returns the user's distinct, non-empty source channel titles
+// (the channels they have videos from), alphabetically — the option list for the
+// feed's channel filter. RLS-scoped via withUser.
+func (s *Store) DistinctChannels(ctx context.Context, userID string) ([]string, error) {
+	var out []string
+	if err := s.withUser(ctx, userID, func(tx pgx.Tx) error {
+		rows, err := tx.Query(ctx,
+			`SELECT DISTINCT channel_title FROM videos
+			  WHERE user_id = $1 AND channel_title IS NOT NULL AND channel_title <> ''
+			  ORDER BY channel_title`, userID)
+		if err != nil {
+			return fmt.Errorf("store: distinct channels: %w", err)
+		}
+		defer rows.Close()
+		for rows.Next() {
+			var c string
+			if err := rows.Scan(&c); err != nil {
+				return fmt.Errorf("store: scan channel: %w", err)
+			}
+			out = append(out, c)
+		}
+		return rows.Err()
+	}); err != nil {
+		return nil, err
+	}
+	return out, nil
+}

internal/adapters/store/videos_test.go

@@ -113,3 +113,29 @@ func TestNewestUnsummarizedVideoIDs(t *testing.T) {
 	require.NoError(t, err)
 	require.Empty(t, none, "limit 0 returns nothing")
 }
+
+func TestUpsertVideoPersistsChannelAndDistinctChannels(t *testing.T) {
+	ctx := context.Background()
+	s := newStore(t)
+	resetDB(t, rawPool(t))
+
+	mk := func(pid, channel string) {
+		v := ytVideo(userA, pid, pid)
+		v.ChannelTitle = channel
+		_, err := s.UpsertVideo(ctx, v)
+		require.NoError(t, err)
+	}
+	mk("aa11111aaaa", "Acme Talks")
+	mk("bb22222bbbb", "Acme Talks") // same channel
+	mk("cc33333cccc", "Zeta Channel")
+	// userB's channel must not leak.
+	vb := ytVideo(userB, "dd44444dddd", "x")
+	vb.ChannelTitle = "Bravo Only"
+	_, err := s.UpsertVideo(ctx, vb)
+	require.NoError(t, err)
+
+	got, err := s.DistinctChannels(ctx, userA)
+	require.NoError(t, err)
+	require.Equal(t, []string{"Acme Talks", "Zeta Channel"}, got,
+		"distinct, alphabetical, user-scoped (no Bravo Only)")
+}

internal/adapters/summarizer/summarizer.go

@@ -1,17 +1,21 @@
 // Package summarizer implements ports.Summarizer backed by the copied llm
-// package's local-Primary -> BYO-Fallback routing (ADR-004). It is the only
+// package's routing (ADR-004, extended by ADR-022). It is the only place content
-// place content ever leaves the engine toward an AI model, so it is also the
+// ever leaves the engine toward an AI model, so it is also the enforcement point
-// enforcement point for the local-first guarantee in
+// for the local-first guarantee in docs/use-cases/ai_routing.feature: endpoints
-// docs/use-cases/ai_routing.feature: a user with no BYO provider configured has
+// are tried in order, locals first, so content only reaches an external model
-// their content sent to the local stack and nowhere else.
+// after every local endpoint has failed — and never at all when no external
+// endpoint is configured.
 package summarizer
 
 import (
+	"bytes"
 	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"strings"
 	"time"
+	"unicode/utf8"
 
 	"gitea.d-ma.be/mathias/tapir/internal/domain"
 )
@@ -29,19 +33,41 @@ type Endpoint struct {
 	Model    string // resolved alias, e.g. "iguana/deepseek-r1-14b"
 }
 
-// Summarizer routes a transcript through the local endpoint first, then the
+// Summarizer routes a transcript through an ordered chain of endpoints, trying
-// optional BYO endpoint. It owns its routing (rather than delegating to
+// each in turn until one returns a parseable summary. It owns its routing
-// llm.Router) so it can record which provider answered and whether the fallback
+// (rather than delegating to llm.Router) so it can record which provider answered
-// was used — information llm.Router collapses away.
+// and whether a fallback was used — information llm.Router collapses away. The
+// chain ordering is the local-first guarantee: callers place local endpoints
+// first and any external endpoint last, so content only reaches an external model
+// after every local endpoint has failed.
 type Summarizer struct {
-	primary  Endpoint
+	endpoints     []Endpoint
-	fallback *Endpoint // nil => no BYO; primary errors are returned, never sent externally
+	maxInputChars int // transcript truncation budget; 0 = no limit
-	now      func() time.Time
+	now           func() time.Time
 }
 
-// New constructs a Summarizer. fallback may be nil (no BYO provider configured).
+// New constructs a Summarizer from a primary endpoint and an optional fallback
+// (the historical local-Primary -> BYO-Fallback shape, ADR-004). A nil fallback
+// means a single-endpoint chain: errors are returned, content never leaves it.
 func New(primary Endpoint, fallback *Endpoint) *Summarizer {
-	return &Summarizer{primary: primary, fallback: fallback, now: time.Now}
+	eps := []Endpoint{primary}
+	if fallback != nil {
+		eps = append(eps, *fallback)
+	}
+	return &Summarizer{endpoints: eps, now: time.Now}
+}
+
+// NewChain constructs a Summarizer over an ordered endpoint chain (ADR-022).
+// endpoints are tried in order; the first to return a parseable summary wins, and
+// FallbackUsed is recorded true for any endpoint past the first. maxInputChars
+// bounds the transcript text sent to every endpoint (0 = unbounded), so a long
+// transcript does not overflow a small-context primary model's window. It panics
+// on an empty chain — a wiring bug, not a runtime condition.
+func NewChain(endpoints []Endpoint, maxInputChars int) *Summarizer {
+	if len(endpoints) == 0 {
+		panic("summarizer: NewChain requires at least one endpoint")
+	}
+	return &Summarizer{endpoints: endpoints, maxInputChars: maxInputChars, now: time.Now}
 }
 
 const systemPrompt = `You are Tapir, a video-summarization assistant.
@@ -53,31 +79,35 @@ Respond with ONLY a JSON object, no prose and no code fences:
 - "takeaways": the actionable conclusions a viewer should leave with.
 Output the JSON object and nothing else.`
 
-// Summarize implements ports.Summarizer.
+// Summarize implements ports.Summarizer. It walks the endpoint chain in order:
+// the first endpoint whose reply parses into a non-empty summary wins. An
+// endpoint is considered failed — and the next one tried — when the model call
+// errors OR when its reply cannot be parsed (a 200 with malformed JSON or a
+// highlights field the model emitted as a bare string). Truncation is applied
+// once, up front, so every endpoint sees the same bounded prompt. When the whole
+// chain fails, the joined error is returned so the engine queues the work for
+// retry and delivers no summary.
 func (s *Summarizer) Summarize(ctx context.Context, v domain.Video, t domain.Transcript) (domain.Summary, error) {
 	if !t.HasText() {
 		return domain.Summary{}, fmt.Errorf("summarize: transcript for video %s has no text", v.ID)
 	}
-	user := buildUserPrompt(v, t)
+	user := buildUserPrompt(v, t, s.maxInputChars)
 
-	// Primary = local stack. Only on its failure is anything sent externally,
+	var errs []error
-	// and only when a BYO fallback is configured.
+	for i, ep := range s.endpoints {
-	out, err := s.primary.Client.Complete(ctx, systemPrompt, user)
+		out, err := ep.Client.Complete(ctx, systemPrompt, user)
-	if err == nil {
+		if err != nil {
-		return s.build(v, s.primary, false, out)
+			errs = append(errs, fmt.Errorf("%s/%s call: %w", ep.Provider, ep.Model, err))
+			continue
+		}
+		sum, perr := s.build(v, ep, i > 0, out)
+		if perr != nil {
+			errs = append(errs, fmt.Errorf("%s/%s output: %w", ep.Provider, ep.Model, perr))
+			continue
+		}
+		return sum, nil
 	}
-
+	return domain.Summary{}, fmt.Errorf("summarize: all %d endpoint(s) failed: %w", len(s.endpoints), errors.Join(errs...))
-	if s.fallback == nil {
-		// No BYO: content was sent to the local stack only. Surface the error so
-		// the engine can queue the work for retry; deliver no summary.
-		return domain.Summary{}, fmt.Errorf("summarize: local AI failed and no BYO provider configured: %w", err)
-	}
-
-	out, ferr := s.fallback.Client.Complete(ctx, systemPrompt, user)
-	if ferr != nil {
-		return domain.Summary{}, fmt.Errorf("summarize: local AI failed: %w; BYO %s failed: %v", err, s.fallback.Provider, ferr)
-	}
-	return s.build(v, *s.fallback, true, out)
 }
 
 func (s *Summarizer) build(v domain.Video, ep Endpoint, fallbackUsed bool, raw string) (domain.Summary, error) {
@@ -89,8 +119,8 @@ func (s *Summarizer) build(v domain.Video, ep Endpoint, fallbackUsed bool, raw s
 		UserID:       v.UserID,
 		VideoID:      v.ID,
 		Summary:      parsed.Summary,
-		Highlights:   parsed.Highlights,
+		Highlights:   []string(parsed.Highlights),
-		Takeaways:    parsed.Takeaways,
+		Takeaways:    []string(parsed.Takeaways),
 		AIProvider:   ep.Provider,
 		AIModel:      ep.Model,
 		FallbackUsed: fallbackUsed,
@@ -98,20 +128,94 @@ func (s *Summarizer) build(v domain.Video, ep Endpoint, fallbackUsed bool, raw s
 	}, nil
 }
 
-func buildUserPrompt(v domain.Video, t domain.Transcript) string {
+func buildUserPrompt(v domain.Video, t domain.Transcript, maxInputChars int) string {
 	var b strings.Builder
 	fmt.Fprintf(&b, "Title: %s\n", v.Title)
 	if v.URL != "" {
 		fmt.Fprintf(&b, "URL: %s\n", v.URL)
 	}
-	fmt.Fprintf(&b, "\nTranscript:\n%s", t.Content)
+	fmt.Fprintf(&b, "\nTranscript:\n%s", truncate(t.Content, maxInputChars))
 	return b.String()
 }
 
+// truncate caps content to max bytes on a UTF-8 rune boundary, appending a
+// marker so the model knows the transcript was cut. A non-positive max (or a
+// content already within budget) returns content unchanged. Bounding the input
+// keeps a long transcript from overflowing a small-context model's window — the
+// production failure mode where koala/phi4-mini's 8k context returned HTTP 400 on
+// a 11.6k-token transcript.
+func truncate(content string, max int) string {
+	if max <= 0 || len(content) <= max {
+		return content
+	}
+	cut := max
+	for cut > 0 && !utf8.RuneStart(content[cut]) {
+		cut--
+	}
+	return content[:cut] + "\n…[transcript truncated to fit the model context]"
+}
+
+// flexStrings is a []string that also unmarshals from a single JSON string or a
+// JSON array of scalars. Small local models (koala/phi4-mini) sometimes emit
+// "highlights": "one point" instead of an array, or mix in a number; rather than
+// fail the whole summary on that quirk, coerce to []string. Empty/whitespace
+// elements are dropped.
+type flexStrings []string
+
+func (f *flexStrings) UnmarshalJSON(b []byte) error {
+	b = bytes.TrimSpace(b)
+	if len(b) == 0 || string(b) == "null" {
+		*f = nil
+		return nil
+	}
+	if b[0] == '[' {
+		var raw []json.RawMessage
+		if err := json.Unmarshal(b, &raw); err != nil {
+			return err
+		}
+		out := make([]string, 0, len(raw))
+		for _, r := range raw {
+			s, err := rawToString(r)
+			if err != nil {
+				return err
+			}
+			if strings.TrimSpace(s) != "" {
+				out = append(out, s)
+			}
+		}
+		*f = out
+		return nil
+	}
+	s, err := rawToString(b)
+	if err != nil {
+		return err
+	}
+	if strings.TrimSpace(s) == "" {
+		*f = nil
+	} else {
+		*f = flexStrings{s}
+	}
+	return nil
+}
+
+// rawToString renders a JSON scalar as text: a quoted string is unquoted; any
+// other scalar (number, bool) is kept as its literal source so no content is lost.
+func rawToString(r json.RawMessage) (string, error) {
+	r = bytes.TrimSpace(r)
+	if len(r) > 0 && r[0] == '"' {
+		var s string
+		if err := json.Unmarshal(r, &s); err != nil {
+			return "", err
+		}
+		return s, nil
+	}
+	return string(r), nil
+}
+
 type parsedSummary struct {
-	Summary    string   `json:"summary"`
+	Summary    string      `json:"summary"`
-	Highlights []string `json:"highlights"`
+	Highlights flexStrings `json:"highlights"`
-	Takeaways  []string `json:"takeaways"`
+	Takeaways  flexStrings `json:"takeaways"`
 }
 
 // parse extracts the JSON object from a model reply. Thinking models (qwen3,

internal/adapters/summarizer/summarizer_test.go

@@ -129,8 +129,8 @@ func TestSummarize_NoBYO_ContentOnlyLocal(t *testing.T) {
 	local := &fakeClient{reply: goodReply}
 	s := New(Endpoint{Client: local, Provider: "local", Model: "iguana/deepseek-r1-14b"}, nil)
 
-	if s.fallback != nil {
+	if len(s.endpoints) != 1 {
-		t.Fatal("no BYO configured but fallback endpoint is non-nil")
+		t.Fatalf("no BYO configured but chain has %d endpoints, want 1", len(s.endpoints))
 	}
 	for i := 0; i < 3; i++ {
 		sum, err := s.Summarize(context.Background(), testVideo(), testTranscript())
@@ -176,3 +176,97 @@ func TestParse_EmptySummaryRejected(t *testing.T) {
 		t.Fatal("want error for empty summary (thinking model returned no content)")
 	}
 }
+
+// parse tolerates a small model emitting "highlights" as a bare string instead
+// of an array — the production koala/phi4-mini quirk that errored with
+// "cannot unmarshal string into Go struct field ... highlights of type []string".
+func TestParse_ToleratesStringHighlights(t *testing.T) {
+	p, err := parse(`{"summary":"s","highlights":"one big point","takeaways":["a","b"]}`)
+	if err != nil {
+		t.Fatalf("parse: %v", err)
+	}
+	if len(p.Highlights) != 1 || p.Highlights[0] != "one big point" {
+		t.Errorf("highlights = %v, want [\"one big point\"]", p.Highlights)
+	}
+	if len(p.Takeaways) != 2 {
+		t.Errorf("takeaways = %v, want 2", p.Takeaways)
+	}
+}
+
+// Chain: an endpoint that returns a 200 with unparseable output is treated as a
+// failure, and the next endpoint in the chain is tried. This is the case the old
+// primary->fallback shape missed — a parse error short-circuited instead of
+// falling back.
+func TestSummarize_FallsBackOnMalformedOutput(t *testing.T) {
+	bad := &fakeClient{reply: `{"summary": not json`}
+	good := &fakeClient{reply: goodReply}
+	s := NewChain([]Endpoint{
+		{Client: bad, Provider: "local", Model: "koala/phi4-mini"},
+		{Client: good, Provider: "local", Model: "koala/phi4-14b"},
+	}, 0)
+
+	sum, err := s.Summarize(context.Background(), testVideo(), testTranscript())
+	if err != nil {
+		t.Fatalf("Summarize: %v", err)
+	}
+	if sum.AIModel != "koala/phi4-14b" {
+		t.Errorf("AIModel = %q, want koala/phi4-14b (fell back past malformed primary)", sum.AIModel)
+	}
+	if !sum.FallbackUsed {
+		t.Error("FallbackUsed = false, want true")
+	}
+	if bad.calls != 1 || good.calls != 1 {
+		t.Errorf("calls: bad=%d good=%d, want 1 and 1", bad.calls, good.calls)
+	}
+}
+
+// Chain: when every endpoint fails, no summary is produced and the joined error
+// names each failure so the engine queues the work for retry.
+func TestSummarize_ChainAllEndpointsFail(t *testing.T) {
+	a := &fakeClient{err: errors.New("context overflow")}
+	b := &fakeClient{reply: "not even json"}
+	s := NewChain([]Endpoint{
+		{Client: a, Provider: "local", Model: "m1"},
+		{Client: b, Provider: "berget", Model: "m2"},
+	}, 0)
+
+	if _, err := s.Summarize(context.Background(), testVideo(), testTranscript()); err == nil {
+		t.Fatal("want error when all endpoints fail")
+	}
+	if a.calls != 1 || b.calls != 1 {
+		t.Errorf("calls: a=%d b=%d, want 1 and 1", a.calls, b.calls)
+	}
+}
+
+// A transcript longer than the chain's input budget is truncated before it
+// reaches any model, so a small-context primary does not overflow its window.
+func TestSummarize_TruncatesLongTranscript(t *testing.T) {
+	local := &fakeClient{reply: goodReply}
+	const budget = 100
+	s := NewChain([]Endpoint{{Client: local, Provider: "local", Model: "m"}}, budget)
+
+	long := domain.Transcript{
+		VideoID: "vid-1", UserID: "user-1", Source: domain.SourceCaptions,
+		Content: strings.Repeat("word ", 1000), // 5000 bytes, well over budget
+	}
+	if _, err := s.Summarize(context.Background(), testVideo(), long); err != nil {
+		t.Fatalf("Summarize: %v", err)
+	}
+	// The prompt carries title/URL framing plus the truncation marker, so allow
+	// headroom over the raw transcript budget — but it must be far below 5000.
+	if len(local.lastUser) > budget+300 {
+		t.Errorf("prompt length = %d, want <= %d (transcript not truncated)", len(local.lastUser), budget+300)
+	}
+	if !strings.Contains(local.lastUser, "truncated") {
+		t.Error("truncation marker missing from prompt")
+	}
+}
+
+func TestNewChain_PanicsOnEmptyChain(t *testing.T) {
+	defer func() {
+		if recover() == nil {
+			t.Fatal("want panic on empty endpoint chain")
+		}
+	}()
+	NewChain(nil, 0)
+}

internal/adapters/youtube/videobyid_test.go

@@ -21,7 +21,7 @@ func TestVideoByID(t *testing.T) {
 		if got := r.URL.Query().Get("part"); got != "snippet" {
 			t.Errorf("expected part=snippet, got %q", got)
 		}
-		_, _ = w.Write([]byte(`{"items":[{"snippet":{"title":"Never Gonna Give You Up","publishedAt":"2026-05-20T09:00:00Z"}}]}`))
+		_, _ = w.Write([]byte(`{"items":[{"snippet":{"title":"Never Gonna Give You Up","channelTitle":"Rick Astley","publishedAt":"2026-05-20T09:00:00Z"}}]}`))
 	})
 
 	v, err := a.VideoByID(context.Background(), "u1", id)
@@ -34,6 +34,9 @@ func TestVideoByID(t *testing.T) {
 	if v.ProviderVideoID != id || v.Title != "Never Gonna Give You Up" {
 		t.Errorf("unexpected video: %+v", v)
 	}
+	if v.ChannelTitle != "Rick Astley" {
+		t.Errorf("ChannelTitle = %q, want Rick Astley", v.ChannelTitle)
+	}
 	if v.Provider != domain.ProviderYouTube || v.URL != "https://www.youtube.com/watch?v="+id {
 		t.Errorf("video not wired correctly: %+v", v)
 	}

internal/adapters/youtube/youtube.go

@@ -234,6 +234,7 @@ func (a *Adapter) NewVideos(ctx context.Context, sub domain.Subscription) ([]dom
 			Provider:        domain.ProviderYouTube,
 			ProviderVideoID: vid,
 			Title:           item.Snippet.Title,
+			ChannelTitle:    sub.ChannelTitle,
 			URL:             "https://www.youtube.com/watch?v=" + vid,
 			PublishedAt:     item.Snippet.PublishedAt,
 		})
@@ -270,6 +271,7 @@ func (a *Adapter) VideoByID(ctx context.Context, userID, videoID string) (domain
 		Provider:        domain.ProviderYouTube,
 		ProviderVideoID: videoID,
 		Title:           it.Snippet.Title,
+		ChannelTitle:    it.Snippet.ChannelTitle,
 		URL:             "https://www.youtube.com/watch?v=" + videoID,
 		PublishedAt:     it.Snippet.PublishedAt,
 	}, nil
@@ -376,8 +378,9 @@ type playlistItemListResponse struct {
 type videoListResponse struct {
 	Items []struct {
 		Snippet struct {
-			Title       string    `json:"title"`
+			Title        string    `json:"title"`
-			PublishedAt time.Time `json:"publishedAt"`
+			ChannelTitle string    `json:"channelTitle"`
+			PublishedAt  time.Time `json:"publishedAt"`
 		} `json:"snippet"`
 	} `json:"items"`
 }

internal/adapters/youtube/youtube_test.go

@@ -131,7 +131,7 @@ func TestNewVideos(t *testing.T) {
 		}`))
 	})
 
-	sub := domain.Subscription{ID: "s1", UserID: "u1", ChannelID: "UC_acme"}
+	sub := domain.Subscription{ID: "s1", UserID: "u1", ChannelID: "UC_acme", ChannelTitle: "Acme Channel"}
 	vids, err := a.NewVideos(context.Background(), sub)
 	if err != nil {
 		t.Fatalf("NewVideos: %v", err)
@@ -143,6 +143,9 @@ func TestNewVideos(t *testing.T) {
 	if v.ProviderVideoID != "vid1" || v.Title != "Designing for Attention" {
 		t.Errorf("unexpected video: %+v", v)
 	}
+	if v.ChannelTitle != "Acme Channel" {
+		t.Errorf("ChannelTitle = %q, want Acme Channel", v.ChannelTitle)
+	}
 	if v.Provider != domain.ProviderYouTube || v.URL != "https://www.youtube.com/watch?v=vid1" {
 		t.Errorf("video not wired correctly: %+v", v)
 	}

internal/config/config.go

@@ -28,8 +28,24 @@ type Config struct {
 	GatewayURL string
 	// GatewayKey authorizes the gateway. Read from env, never committed.
 	GatewayKey string
-	// SummarizerModel is the alias in host/name form, e.g. "koala/phi4-mini".
+	// SummarizerModel is the primary summarizer alias in host/name form, tried
+	// first on every video, e.g. "koala/phi4-mini".
 	SummarizerModel string
+	// FallbackModel is the LOCAL fallback alias tried when the primary fails or
+	// returns unparseable output (ADR-022). Kept local so content stays on the
+	// homelab stack. Empty disables it. Default a bigger-context local model.
+	FallbackModel string
+	// CloudFallbackModel is the worst-case EXTERNAL fallback alias, tried only
+	// after every local endpoint has failed (ADR-022). For client deployments set
+	// this empty so content never leaves the local stack. Default a berget alias.
+	CloudFallbackModel string
+	// SummaryMaxTokens caps the completion budget per summary call. Small-context
+	// models (koala/phi4-mini, 8k) overflow when prompt + max_tokens exceeds the
+	// window; a summary needs only a few hundred tokens, so the default is small.
+	SummaryMaxTokens int
+	// MaxTranscriptChars bounds the transcript text sent to the model so a long
+	// transcript does not overflow a small-context primary. 0 disables truncation.
+	MaxTranscriptChars int
 	// SummarizerTimeout bounds a single completion call. Thinking models are
 	// slow, so the default is generous.
 	SummarizerTimeout time.Duration
@@ -118,6 +134,10 @@ func (c Config) DexConfigured() bool { return strings.TrimSpace(c.OIDCIssuer) !=
 const (
 	defaultGatewayURL            = "http://koala:30401/v1"
 	defaultSummarizerModel       = "koala/phi4-mini"
+	defaultFallbackModel         = "koala/phi4-14b"
+	defaultCloudFallbackModel    = "berget/mistral-small"
+	defaultSummaryMaxTokens      = 1500
+	defaultMaxTranscriptChars    = 18000
 	defaultSummarizerTimeout     = 5 * time.Minute
 	defaultYTTokenRef            = "youtube/refresh_token"
 	defaultYTConnectRedirectURL  = "https://tapir.d-ma.be/oauth/youtube/callback"
@@ -141,6 +161,8 @@ func Load() (Config, error) {
 		GatewayURL:           envOr("TAPIR_GATEWAY_URL", defaultGatewayURL),
 		GatewayKey:           os.Getenv("TAPIR_GATEWAY_KEY"),
 		SummarizerModel:      envOr("TAPIR_SUMMARIZER_MODEL", defaultSummarizerModel),
+		FallbackModel:        lookupOr("TAPIR_FALLBACK_MODEL", defaultFallbackModel),
+		CloudFallbackModel:   lookupOr("TAPIR_CLOUD_FALLBACK_MODEL", defaultCloudFallbackModel),
 		DBDSN:                os.Getenv("TAPIR_DB_DSN"),
 		YTClientID:           os.Getenv("TAPIR_YT_CLIENT_ID"),
 		YTClientSecret:       os.Getenv("TAPIR_YT_CLIENT_SECRET"),
@@ -193,6 +215,21 @@ func Load() (Config, error) {
 	}
 	c.AutoSummarizeWindow = autoWindow
 
+	summaryTokens, err := intOr("TAPIR_SUMMARY_MAX_TOKENS", defaultSummaryMaxTokens)
+	if err != nil {
+		return Config{}, err
+	}
+	c.SummaryMaxTokens = summaryTokens
+
+	maxChars, err := intOr("TAPIR_MAX_TRANSCRIPT_CHARS", defaultMaxTranscriptChars)
+	if err != nil {
+		return Config{}, err
+	}
+	if maxChars < 0 {
+		maxChars = 0
+	}
+	c.MaxTranscriptChars = maxChars
+
 	onboard, err := intOr("TAPIR_ONBOARD_SUMMARIZE_COUNT", defaultOnboardSummarizeCount)
 	if err != nil {
 		return Config{}, err
@@ -269,6 +306,17 @@ func envOr(key, fallback string) string {
 	return fallback
 }
 
+// lookupOr returns the env value when the key is PRESENT (even if empty), else
+// fallback. Unlike envOr it lets an explicit empty value override the default —
+// needed to DISABLE an optional fallback model (e.g. set the cloud fallback empty
+// for a client deployment so content never leaves the local stack).
+func lookupOr(key, fallback string) string {
+	if v, ok := os.LookupEnv(key); ok {
+		return v
+	}
+	return fallback
+}
+
 func intOr(key string, fallback int) (int, error) {
 	v := os.Getenv(key)
 	if v == "" {

internal/config/config_test.go

@@ -1,11 +1,29 @@
 package config
 
 import (
+	"os"
 	"strings"
 	"testing"
 	"time"
 )
 
+// unset removes an env key for the duration of the test, restoring it after.
+// Needed to observe a default for a key read with LookupEnv (where present-empty
+// means "explicitly disabled", not "use default").
+func unset(t *testing.T, key string) {
+	t.Helper()
+	if old, ok := os.LookupEnv(key); ok {
+		t.Cleanup(func() {
+			if err := os.Setenv(key, old); err != nil {
+				t.Fatalf("restore %s: %v", key, err)
+			}
+		})
+	}
+	if err := os.Unsetenv(key); err != nil {
+		t.Fatalf("unset %s: %v", key, err)
+	}
+}
+
 // setEnv sets env vars for the test and clears them afterward, so cases don't
 // leak into one another. t.Setenv handles restoration.
 func setEnv(t *testing.T, kv map[string]string) {
@@ -53,6 +71,46 @@ func TestLoad_AppliesDefaults(t *testing.T) {
 	}
 }
 
+func TestLoad_SummarizerChainDefaults(t *testing.T) {
+	setEnv(t, map[string]string{
+		"TAPIR_SUMMARIZER_MODEL":     "",
+		"TAPIR_SUMMARY_MAX_TOKENS":   "",
+		"TAPIR_MAX_TRANSCRIPT_CHARS": "",
+	})
+	unset(t, "TAPIR_FALLBACK_MODEL")
+	unset(t, "TAPIR_CLOUD_FALLBACK_MODEL")
+
+	c, err := Load()
+	if err != nil {
+		t.Fatalf("Load: %v", err)
+	}
+	if c.FallbackModel != defaultFallbackModel {
+		t.Errorf("FallbackModel = %q, want %q", c.FallbackModel, defaultFallbackModel)
+	}
+	if c.CloudFallbackModel != defaultCloudFallbackModel {
+		t.Errorf("CloudFallbackModel = %q, want %q", c.CloudFallbackModel, defaultCloudFallbackModel)
+	}
+	if c.SummaryMaxTokens != defaultSummaryMaxTokens {
+		t.Errorf("SummaryMaxTokens = %d, want %d", c.SummaryMaxTokens, defaultSummaryMaxTokens)
+	}
+	if c.MaxTranscriptChars != defaultMaxTranscriptChars {
+		t.Errorf("MaxTranscriptChars = %d, want %d", c.MaxTranscriptChars, defaultMaxTranscriptChars)
+	}
+}
+
+// An explicitly empty cloud-fallback env disables external routing — the lever a
+// client deployment pulls so content never leaves the local stack.
+func TestLoad_EmptyCloudFallbackDisables(t *testing.T) {
+	t.Setenv("TAPIR_CLOUD_FALLBACK_MODEL", "")
+	c, err := Load()
+	if err != nil {
+		t.Fatalf("Load: %v", err)
+	}
+	if c.CloudFallbackModel != "" {
+		t.Errorf("CloudFallbackModel = %q, want empty (disabled)", c.CloudFallbackModel)
+	}
+}
+
 func TestLoad_OnboardSummarizeCount(t *testing.T) {
 	cases := []struct {
 		name, env string

internal/domain/domain.go

@@ -73,6 +73,7 @@ type Video struct {
 	Provider        Provider
 	ProviderVideoID string
 	Title           string
+	ChannelTitle    string
 	URL             string
 	PublishedAt     time.Time
 	SeenAt          time.Time

internal/ports/ports.go

@@ -27,6 +27,26 @@ type Summarizer interface {
 	Summarize(ctx context.Context, v domain.Video, t domain.Transcript) (domain.Summary, error)
 }
 
+// TranscriptStore persists transcripts as shared, video-keyed public content
+// (ADR-021). It is keyed by the cross-user dedup key (provider, providerVideoID)
+// — the video's public identity, NOT Tapir's per-user videos.id — and holds only
+// public caption content, so it is deliberately NOT user-scoped: two users who
+// share a video share the one row. The engine reads it before any caption fetch
+// so re-analysis never re-touches YouTube (ADR-010/014).
+type TranscriptStore interface {
+	// GetTranscript returns the stored transcript for a video and whether one
+	// exists. A stored Source == SourceNone (captions permanently absent) is a
+	// real hit: ok is true and HasText() is false, so callers skip without
+	// re-fetching. A transient rate-limit is never stored, so it never appears
+	// here as a false absence.
+	GetTranscript(ctx context.Context, provider, providerVideoID string) (t domain.Transcript, ok bool, err error)
+	// SaveTranscript upserts the transcript for (provider, providerVideoID). Only
+	// terminal outcomes are persisted: SourceCaptions (with text) or SourceNone.
+	// SourceRateLimited must NOT be passed — it is a per-user retry (ADR-014), not
+	// a shared terminal state.
+	SaveTranscript(ctx context.Context, provider, providerVideoID string, t domain.Transcript) error
+}
+
 // Sink delivers a summary to a destination (user store, brain, ...).
 // Implementations fail independently of one another.
 type Sink interface {

internal/usecase/engine.go

@@ -27,6 +27,13 @@ type Engine struct {
 	AI     ports.Summarizer
 	Sinks  []ports.Sink
 
+	// Transcripts, when set, is the shared transcript cache (ADR-021): the engine
+	// reads it before any caption fetch and writes resolved transcripts back, so
+	// re-analysis — the same user re-summarizing, or a second user with the same
+	// video — never re-touches YouTube (ADR-010/014). Optional: nil disables
+	// persistence (fetch every time), keeping the pure-core/scaffold wiring valid.
+	Transcripts ports.TranscriptStore
+
 	// processed dedups videos within this engine's lifetime so a video is not
 	// summarized twice when the watcher sees it again. Durable cross-restart
 	// dedup is the store's concern (a resolved TRANSCRIPT / existing SUMMARY,
@@ -57,9 +64,9 @@ type ProcessResult struct {
 // resolve transcript -> (summarize -> deliver) | skip.
 // See docs/use-cases/summarize_new_video.feature.
 func (e *Engine) ProcessNewVideo(ctx context.Context, v domain.Video) (ProcessResult, error) {
-	t, err := e.Source.FetchTranscript(ctx, v)
+	t, err := e.resolveTranscript(ctx, v)
 	if err != nil {
-		return ProcessResult{Video: v}, fmt.Errorf("fetch transcript: %w", err)
+		return ProcessResult{Video: v}, err
 	}
 	if !t.HasText() {
 		// No usable transcript: record the skip, produce no summary, deliver nothing
@@ -86,6 +93,39 @@ func (e *Engine) ProcessNewVideo(ctx context.Context, v domain.Video) (ProcessRe
 	return ProcessResult{Video: v, Summary: &sum, TranscriptSource: string(t.Source)}, errors.Join(errs...)
 }
 
+// resolveTranscript returns v's transcript, reading the shared store first
+// (ADR-021): a stored transcript — including a stored SourceNone (captions
+// permanently absent) — is returned without touching YouTube, so re-analysis
+// never re-fetches. On a store miss it fetches through the source (which gates
+// the caption call, ADR-014) and persists the terminal outcome so the next
+// analysis, for any user, reads from the store. A transient SourceRateLimited is
+// returned to the caller (the runner stamps a per-user backoff) but never stored,
+// so persistence can never mask a 429 as a permanent "no transcript". When no
+// TranscriptStore is wired the engine simply fetches every time.
+func (e *Engine) resolveTranscript(ctx context.Context, v domain.Video) (domain.Transcript, error) {
+	if e.Transcripts != nil {
+		stored, ok, err := e.Transcripts.GetTranscript(ctx, string(v.Provider), v.ProviderVideoID)
+		if err != nil {
+			return domain.Transcript{}, fmt.Errorf("get stored transcript: %w", err)
+		}
+		if ok {
+			return stored, nil
+		}
+	}
+
+	t, err := e.Source.FetchTranscript(ctx, v)
+	if err != nil {
+		return domain.Transcript{}, fmt.Errorf("fetch transcript: %w", err)
+	}
+
+	if e.Transcripts != nil && t.Source != domain.SourceRateLimited {
+		if err := e.Transcripts.SaveTranscript(ctx, string(v.Provider), v.ProviderVideoID, t); err != nil {
+			return domain.Transcript{}, fmt.Errorf("save transcript: %w", err)
+		}
+	}
+	return t, nil
+}
+
 // ProcessNewVideos walks a user's subscriptions and processes each newly seen
 // video. Only videos surfaced via the user's subscriptions are considered, so a
 // channel the user is not subscribed to is never processed. A video already

internal/usecase/engine_transcript_test.go

@@ -0,0 +1,187 @@
+package usecase
+
+import (
+	"context"
+	"testing"
+
+	"gitea.d-ma.be/mathias/tapir/internal/domain"
+)
+
+// These tests pin the ADR-021 read-stored-first behaviour at the engine core:
+// a stored transcript is summarized without re-touching the source, a miss
+// fetches once and persists, and a transient rate-limit is never cached.
+
+type recordingSource struct {
+	transcript domain.Transcript
+	fetchCalls int
+}
+
+func (s *recordingSource) ListSubscriptions(context.Context, string) ([]domain.Subscription, error) {
+	return nil, nil
+}
+
+func (s *recordingSource) NewVideos(context.Context, domain.Subscription) ([]domain.Video, error) {
+	return nil, nil
+}
+
+func (s *recordingSource) FetchTranscript(context.Context, domain.Video) (domain.Transcript, error) {
+	s.fetchCalls++
+	return s.transcript, nil
+}
+
+type fakeTranscriptStore struct {
+	stored map[string]domain.Transcript
+	saves  int
+}
+
+func newFakeTranscriptStore() *fakeTranscriptStore {
+	return &fakeTranscriptStore{stored: make(map[string]domain.Transcript)}
+}
+
+func (f *fakeTranscriptStore) key(provider, id string) string { return provider + "|" + id }
+
+func (f *fakeTranscriptStore) GetTranscript(_ context.Context, provider, id string) (domain.Transcript, bool, error) {
+	t, ok := f.stored[f.key(provider, id)]
+	return t, ok, nil
+}
+
+func (f *fakeTranscriptStore) SaveTranscript(_ context.Context, provider, id string, t domain.Transcript) error {
+	f.saves++
+	f.stored[f.key(provider, id)] = t
+	return nil
+}
+
+type countingSummarizer struct{ calls int }
+
+func (c *countingSummarizer) Summarize(_ context.Context, v domain.Video, _ domain.Transcript) (domain.Summary, error) {
+	c.calls++
+	return domain.Summary{VideoID: v.ID, UserID: v.UserID, Summary: "s", AIProvider: "local"}, nil
+}
+
+type nopSink struct{}
+
+func (nopSink) Name() string                                  { return "nop" }
+func (nopSink) Deliver(context.Context, domain.Summary) error { return nil }
+
+func testVideo() domain.Video {
+	return domain.Video{ID: "v1", UserID: "u1", Provider: domain.ProviderYouTube, ProviderVideoID: "yt1"}
+}
+
+func TestProcessNewVideo_StoredTranscriptSkipsFetch(t *testing.T) {
+	src := &recordingSource{}
+	ts := newFakeTranscriptStore()
+	ts.stored[ts.key("youtube", "yt1")] = domain.Transcript{Source: domain.SourceCaptions, Content: "stored words"}
+	sum := &countingSummarizer{}
+	eng := NewEngine(src, sum, nopSink{})
+	eng.Transcripts = ts
+
+	res, err := eng.ProcessNewVideo(context.Background(), testVideo())
+	if err != nil {
+		t.Fatalf("ProcessNewVideo: %v", err)
+	}
+	if src.fetchCalls != 0 {
+		t.Fatalf("stored transcript must not re-fetch from source; got %d fetches", src.fetchCalls)
+	}
+	if ts.saves != 0 {
+		t.Fatalf("a store hit must not re-save; got %d saves", ts.saves)
+	}
+	if sum.calls != 1 || res.Summary == nil {
+		t.Fatalf("expected a summary from the stored transcript; calls=%d summary=%v", sum.calls, res.Summary)
+	}
+}
+
+func TestProcessNewVideo_StoreMissFetchesAndPersists(t *testing.T) {
+	src := &recordingSource{transcript: domain.Transcript{Source: domain.SourceCaptions, Language: "en", Content: "fetched words"}}
+	ts := newFakeTranscriptStore()
+	sum := &countingSummarizer{}
+	eng := NewEngine(src, sum, nopSink{})
+	eng.Transcripts = ts
+
+	if _, err := eng.ProcessNewVideo(context.Background(), testVideo()); err != nil {
+		t.Fatalf("ProcessNewVideo: %v", err)
+	}
+	if src.fetchCalls != 1 {
+		t.Fatalf("a store miss must fetch exactly once; got %d", src.fetchCalls)
+	}
+	if ts.saves != 1 {
+		t.Fatalf("a fetched transcript must be persisted; got %d saves", ts.saves)
+	}
+	got, ok, _ := ts.GetTranscript(context.Background(), "youtube", "yt1")
+	if !ok || got.Content != "fetched words" {
+		t.Fatalf("persisted transcript not readable back: ok=%v content=%q", ok, got.Content)
+	}
+}
+
+// The second summarize of the same video reads the persisted transcript and does
+// NOT re-fetch — the primary ADR-021 win, proven end to end at the engine.
+func TestProcessNewVideo_SecondSummarizeDoesNotRefetch(t *testing.T) {
+	src := &recordingSource{transcript: domain.Transcript{Source: domain.SourceCaptions, Content: "words"}}
+	ts := newFakeTranscriptStore()
+	eng := NewEngine(src, &countingSummarizer{}, nopSink{})
+	eng.Transcripts = ts
+
+	for i := 0; i < 2; i++ {
+		if _, err := eng.ProcessNewVideo(context.Background(), testVideo()); err != nil {
+			t.Fatalf("pass %d: %v", i, err)
+		}
+	}
+	if src.fetchCalls != 1 {
+		t.Fatalf("the second summarize must reuse the stored transcript; got %d fetches", src.fetchCalls)
+	}
+}
+
+// A stored "no captions" outcome short-circuits before both fetch and summarize.
+func TestProcessNewVideo_StoredNoneSkipsFetchAndSummarize(t *testing.T) {
+	src := &recordingSource{}
+	ts := newFakeTranscriptStore()
+	ts.stored[ts.key("youtube", "yt1")] = domain.Transcript{Source: domain.SourceNone}
+	sum := &countingSummarizer{}
+	eng := NewEngine(src, sum, nopSink{})
+	eng.Transcripts = ts
+
+	res, err := eng.ProcessNewVideo(context.Background(), testVideo())
+	if err != nil {
+		t.Fatalf("ProcessNewVideo: %v", err)
+	}
+	if !res.Skipped {
+		t.Fatal("a stored SourceNone must skip")
+	}
+	if src.fetchCalls != 0 || sum.calls != 0 {
+		t.Fatalf("stored none must neither fetch nor summarize; fetches=%d calls=%d", src.fetchCalls, sum.calls)
+	}
+}
+
+// A transient 429 is surfaced (so the runner backs off per-user) but never cached
+// as a shared terminal state — otherwise it would mask a rate-limit as permanent.
+func TestProcessNewVideo_RateLimitedIsNotPersisted(t *testing.T) {
+	src := &recordingSource{transcript: domain.Transcript{Source: domain.SourceRateLimited}}
+	ts := newFakeTranscriptStore()
+	eng := NewEngine(src, &countingSummarizer{}, nopSink{})
+	eng.Transcripts = ts
+
+	res, err := eng.ProcessNewVideo(context.Background(), testVideo())
+	if err != nil {
+		t.Fatalf("ProcessNewVideo: %v", err)
+	}
+	if !res.Skipped || res.TranscriptSource != string(domain.SourceRateLimited) {
+		t.Fatalf("expected a rate-limited skip; skipped=%v source=%q", res.Skipped, res.TranscriptSource)
+	}
+	if ts.saves != 0 {
+		t.Fatalf("a transient rate-limit must not be persisted; got %d saves", ts.saves)
+	}
+}
+
+// With no TranscriptStore wired the engine fetches every time (back-compat).
+func TestProcessNewVideo_NilStoreFetchesEveryTime(t *testing.T) {
+	src := &recordingSource{transcript: domain.Transcript{Source: domain.SourceCaptions, Content: "words"}}
+	eng := NewEngine(src, &countingSummarizer{}, nopSink{})
+
+	for i := 0; i < 2; i++ {
+		if _, err := eng.ProcessNewVideo(context.Background(), testVideo()); err != nil {
+			t.Fatalf("pass %d: %v", i, err)
+		}
+	}
+	if src.fetchCalls != 2 {
+		t.Fatalf("nil store must fetch every time; got %d", src.fetchCalls)
+	}
+}

internal/web/handlers.go

@@ -21,6 +21,9 @@ import (
 // fake without a database.
 type Store interface {
 	ListVideos(ctx context.Context, userID string, limit int) ([]store.SummaryRow, error)
+	// DistinctChannels lists the user's source channels — the options for the
+	// feed's channel multi-select filter.
+	DistinctChannels(ctx context.Context, userID string) ([]string, error)
 	GetSummaryByVideo(ctx context.Context, userID, videoID string) (*store.SummaryRow, error)
 	GetVideoRow(ctx context.Context, userID, videoID string) (*store.SummaryRow, error)
 	ActionsFor(ctx context.Context, userID string, videoIDs []string) (map[string][]string, error)
@@ -196,7 +199,7 @@ func (a *App) handleList(w http.ResponseWriter, r *http.Request) {
 	}
 	q := r.URL.Query()
 	f := Filter{
-		Channel:        q.Get("channel"),
+		Channels:       nonEmptyStrings(q["channel"]),
 		From:           q.Get("from"),
 		To:             q.Get("to"),
 		OnlySummarized: q.Get("summarized") == "1",
@@ -211,25 +214,39 @@ func (a *App) handleList(w http.ResponseWriter, r *http.Request) {
 	rows := f.apply(allRows)
 	buckets := bucketRows(rows, a.recencyCutoff())
 
-	// hasConnected drives the empty state: a fresh account with a connection but
+	// Channel options for the multi-select filter (the user's source channels).
-	// no discovery pass yet has zero rows, and we want it to read "connected,
+	channels, err := a.Store.DistinctChannels(r.Context(), userID)
-	// summaries land gradually" rather than "nothing here". Only needed when the
+	if err != nil {
-	// list is empty.
+		a.serverError(w, r, "distinct channels", err)
-	hasConnected := false
+		return
-	if buckets.empty() {
+	}
-		conns, err := a.Store.ConnectionsForUser(r.Context(), userID)
+
-		if err != nil {
+	// hasConnected drives both the paste box (shown to ANY connected user, #2) and
-			a.serverError(w, r, "connections for user", err)
+	// the empty-state copy (a fresh account with a connection but no discovery pass
-			return
+	// yet reads "connected, summaries land gradually" rather than "nothing here").
-		}
+	// Computed every render — not only when empty — so a user with videos still
-		hasConnected = len(conns) > 0
+	// gets the paste box.
+	conns, err := a.Store.ConnectionsForUser(r.Context(), userID)
+	if err != nil {
+		a.serverError(w, r, "connections for user", err)
+		return
+	}
+	hasConnected := len(conns) > 0
+
+	// Summarization mode drives the backlog copy: an auto user is told summaries
+	// land gradually; a manual user is told to click Summarize (the first pilot
+	// user sat in manual mode reading "land automatically" and waited forever).
+	autoSummarize, err := a.Store.GetAutoSummarize(r.Context(), userID)
+	if err != nil {
+		a.serverError(w, r, "summarize mode", err)
+		return
 	}
 
 	if isHTMX(r) {
-		a.render(w, r, summaryList(buckets, hasConnected))
+		a.render(w, r, summaryList(buckets, hasConnected, autoSummarize))
 		return
 	}
-	a.render(w, r, ListPage(buckets, f, stats, takeFlash(w, r), hasConnected))
+	a.render(w, r, ListPage(buckets, f, stats, takeFlash(w, r), hasConnected, channels, autoSummarize))
 }
 
 // handleDetail renders one summary in full (highlights, takeaways, action group).

internal/web/handlers_test.go

@@ -207,13 +207,15 @@ func TestListChannelFilter(t *testing.T) {
 	resetDB(t, p)
 	require.NoError(t, deliver(ctx, app, videoX, "body x"))
 	seedVideo(t, p, videoX, "X Title", "https://x", time.Time{})
+	_, err := p.Exec(ctx, `UPDATE videos SET channel_title = 'Acme Channel' WHERE id = $1`, videoX)
+	require.NoError(t, err)
 
-	// Channel is "youtube" for seeded rows; a non-matching filter hides them.
+	// Selecting a different channel hides the row; selecting its channel shows it.
-	rec := do(t, app, httptest.NewRequest(http.MethodGet, "/?channel=vimeo", nil))
+	rec := do(t, app, httptest.NewRequest(http.MethodGet, "/?channel=Other+Channel", nil))
 	require.Equal(t, http.StatusOK, rec.Code)
 	require.NotContains(t, body(t, rec), "X Title")
 
-	rec = do(t, app, httptest.NewRequest(http.MethodGet, "/?channel=youtube", nil))
+	rec = do(t, app, httptest.NewRequest(http.MethodGet, "/?channel=Acme+Channel", nil))
 	require.Contains(t, body(t, rec), "X Title")
 }
 
@@ -475,3 +477,36 @@ func postAction(t *testing.T, app *web.App, videoID, action string, htmx bool) *
 	}
 	return do(t, app, req)
 }
+
+// TestListManualModeBannerCopy: a manual-mode user with un-summarized videos
+// sees the manual prompt (click Summarize), NOT the "summaries land
+// automatically" copy that misled the first pilot user into waiting forever.
+func TestListManualModeBannerCopy(t *testing.T) {
+	ctx := context.Background()
+	app := newApp(t)
+	p := rawPool(t)
+	resetDB(t, p)
+	seedVideo(t, p, videoX, "X Title", "https://x", time.Time{}) // pending, un-summarized
+	require.NoError(t, app.Store.SetAutoSummarize(ctx, userID, false))
+
+	html := body(t, do(t, app, httptest.NewRequest(http.MethodGet, "/", nil)))
+	require.Contains(t, html, "Manual mode")
+	require.Contains(t, html, "are not summarized automatically")
+	require.NotContains(t, html, "land gradually",
+		"manual-mode user must not be told summaries arrive automatically")
+}
+
+// TestListAutoModeBannerCopy: an auto-mode user with a backlog sees the
+// gradual-delivery copy, not the manual prompt.
+func TestListAutoModeBannerCopy(t *testing.T) {
+	ctx := context.Background()
+	app := newApp(t)
+	p := rawPool(t)
+	resetDB(t, p)
+	seedVideo(t, p, videoX, "X Title", "https://x", time.Time{})
+	require.NoError(t, app.Store.SetAutoSummarize(ctx, userID, true))
+
+	html := body(t, do(t, app, httptest.NewRequest(http.MethodGet, "/", nil)))
+	require.Contains(t, html, "land gradually")
+	require.NotContains(t, html, "are not summarized automatically")
+}

internal/web/paste_handler_test.go

@@ -7,6 +7,7 @@ import (
 	"net/url"
 	"strings"
 	"testing"
+	"time"
 
 	"github.com/stretchr/testify/require"
 
@@ -111,3 +112,23 @@ func TestPasteDedupNoDuplicate(t *testing.T) {
 		userID).Scan(&count))
 	require.Equal(t, 1, count, "pasting the same video twice must not duplicate the row")
 }
+
+func TestListShowsPasteFormForConnectedUserWithVideos(t *testing.T) {
+	app := newApp(t)
+	resetDB(t, rawPool(t))
+	app.Fetcher = &fakeFetcher{title: "x"}
+	p := rawPool(t)
+
+	// Connected user with a non-empty feed (the case the bug missed: hasConnected
+	// was only computed for an empty feed).
+	_, err := p.Exec(context.Background(),
+		`INSERT INTO video_connections (user_id, provider, token_ref, status)
+		 VALUES ($1, 'youtube', 'youtube/x/refresh_token', 'active')`, userID)
+	require.NoError(t, err)
+	seedVideo(t, p, "11111111-1111-1111-1111-111111111111", "A talk", "https://youtu.be/aaaaaaaaaaa", time.Now())
+
+	rec := do(t, app, httptest.NewRequest(http.MethodGet, "/", nil))
+	require.Equal(t, http.StatusOK, rec.Code)
+	require.Contains(t, body(t, rec), `action="/paste"`,
+		"a connected user must see the paste box even when the feed has videos")
+}

internal/web/paste_test.go

@@ -1,6 +1,12 @@
 package web
 
-import "testing"
+import (
+	"bytes"
+	"context"
+	"gitea.d-ma.be/mathias/tapir/internal/adapters/store"
+	"strings"
+	"testing"
+)
 
 func TestParseYouTubeVideoID(t *testing.T) {
 	const id = "dQw4w9WgXcQ"
@@ -55,3 +61,37 @@ func TestParseYouTubeVideoID(t *testing.T) {
 		})
 	}
 }
+
+func TestListPageShowsPasteFormOnlyWhenConnected(t *testing.T) {
+	render := func(connected bool) string {
+		var buf bytes.Buffer
+		if err := ListPage(listBuckets{}, Filter{}, PipelineStats{}, "", connected, nil, true).Render(context.Background(), &buf); err != nil {
+			t.Fatalf("render: %v", err)
+		}
+		return buf.String()
+	}
+
+	html := render(true)
+	if !strings.Contains(html, `name="url"`) || !strings.Contains(html, `action="/paste"`) {
+		t.Errorf("connected feed must show the paste form")
+	}
+	if strings.Contains(render(false), `name="url"`) {
+		t.Errorf("disconnected feed must not show the paste form")
+	}
+}
+
+func TestFilterMatchesMultipleChannels(t *testing.T) {
+	f := Filter{Channels: []string{"Acme", "Zeta"}}
+	row := func(ch string) store.SummaryRow { return store.SummaryRow{ChannelTitle: ch, Summarized: true} }
+
+	rows := []store.SummaryRow{row("Acme"), row("Beta"), row("Zeta")}
+	got := f.apply(rows)
+	if len(got) != 2 || got[0].ChannelTitle != "Acme" || got[1].ChannelTitle != "Zeta" {
+		t.Fatalf("multi-channel filter = %+v, want Acme+Zeta only", got)
+	}
+
+	// Empty selection = no channel constraint (all pass).
+	if n := len(Filter{}.apply(rows)); n != 3 {
+		t.Fatalf("no channel filter should pass all rows, got %d", n)
+	}
+}

internal/web/view.go

@@ -2,6 +2,7 @@ package web
 
 import (
 	"regexp"
+	"slices"
 	"strings"
 	"time"
 	"unicode/utf8"
@@ -333,7 +334,7 @@ type flashView struct {
 // flashMessages maps each flash code to its banner. An unknown code renders no
 // banner (flashFor returns ok=false), so a forged cookie value is inert.
 var flashMessages = map[string]flashView{
-	flashConnected:     {"success", "YouTube account connected."},
+	flashConnected:     {"success", "YouTube account connected — finding your subscriptions. Your newest videos will appear below as they're summarized."},
 	flashConnectFailed: {"error", "Could not connect your YouTube account. Please try again."},
 	flashDisconnected:  {"success", "Account disconnected."},
 	flashDeleted:       {"success", "Your account and all its data were deleted."},
@@ -469,7 +470,7 @@ func (b listBuckets) empty() bool {
 // Dates are kept as the raw YYYY-MM-DD strings so the form re-renders the user's
 // input verbatim; parsing happens in matchFilter.
 type Filter struct {
-	Channel        string
+	Channels       []string // selected channel titles; empty = all channels
 	From           string
 	To             string
 	OnlySummarized bool // show only videos that have a summary
@@ -480,7 +481,28 @@ type Filter struct {
 // filter) the bar is hidden so the connect CTA stands alone (UX review C1); a
 // filter that happens to match nothing still shows the bar so it can be cleared.
 func (f Filter) active() bool {
-	return f.Channel != "" || f.From != "" || f.To != "" || f.OnlySummarized
+	return len(f.Channels) > 0 || f.From != "" || f.To != "" || f.OnlySummarized
+}
+
+// HasChannel reports whether a channel is currently selected (drives the
+// multi-select's selected state in the view).
+func (f Filter) HasChannel(c string) bool {
+	return slices.Contains(f.Channels, c)
+}
+
+// nonEmptyStrings drops blank entries. A channel multi-select submits real
+// channel titles; this guards against a stray empty value reaching the filter.
+func nonEmptyStrings(ss []string) []string {
+	out := ss[:0:0]
+	for _, s := range ss {
+		if strings.TrimSpace(s) != "" {
+			out = append(out, s)
+		}
+	}
+	if len(out) == 0 {
+		return nil
+	}
+	return out
 }
 
 // matches reports whether a row satisfies the filter. Channel is an exact match;
@@ -491,7 +513,7 @@ func (f Filter) matches(r store.SummaryRow) bool {
 	if f.OnlySummarized && !r.Summarized {
 		return false
 	}
-	if f.Channel != "" && r.Channel != f.Channel {
+	if len(f.Channels) > 0 && !slices.Contains(f.Channels, r.ChannelTitle) {
 		return false
 	}
 	if from, ok := parseDate(f.From); ok {
@@ -521,7 +543,7 @@ func parseDate(s string) (time.Time, bool) {
 
 // apply returns the subset of rows matching the filter, preserving order.
 func (f Filter) apply(rows []store.SummaryRow) []store.SummaryRow {
-	if f.Channel == "" && f.From == "" && f.To == "" && !f.OnlySummarized {
+	if len(f.Channels) == 0 && f.From == "" && f.To == "" && !f.OnlySummarized {
 		return rows
 	}
 	out := rows[:0:0]

internal/web/views.templ

@@ -104,23 +104,35 @@ templ flashBanner(code string) {
 // #summary-list region; a non-HTMX request renders the whole page. flash carries
 // a one-shot notification (e.g. "connected", "registered") surfaced on arrival
 // after a POST→redirect.
-templ ListPage(b listBuckets, f Filter, stats PipelineStats, flash string, hasConnected bool) {
+templ ListPage(b listBuckets, f Filter, stats PipelineStats, flash string, hasConnected bool, channels []string, autoSummarize bool) {
 	@Layout("Tapir — Summaries") {
 		@flashBanner(flash)
+		if hasConnected {
+			@pasteForm()
+		}
 		if !b.empty() || f.active() {
-			@filterForm(f)
+			@filterForm(f, channels)
 		}
 		if stats.RateLimited > 0 || stats.Pending > 0 || stats.NoText > 0 {
 			@pipelineBar(stats)
 		}
-		if stats.RateLimited+stats.Pending > 0 {
+		if (stats.RateLimited+stats.Pending) > 0 && autoSummarize {
 			<p class="pipeline-note muted">
 				Tapir fetches captions slowly on purpose, to respect YouTube's limits —
 				new summaries land gradually. Check back tomorrow.
 			</p>
 		}
+		if (stats.RateLimited+stats.Pending) > 0 && !autoSummarize {
+			<p class="pipeline-note muted">
+				You are in Manual mode: new videos appear here but are not summarized
+				automatically. Use the Summarize button on the ones you want.
+			</p>
+			<p class="pipeline-note muted">
+				<a href="/account">Switch to Automatic</a> to have new videos summarized for you.
+			</p>
+		}
 		<div id="summary-list">
-			@summaryList(b, hasConnected)
+			@summaryList(b, hasConnected, autoSummarize)
 		</div>
 	}
 }
@@ -143,7 +155,29 @@ templ pipelineBar(s PipelineStats) {
 	</div>
 }
 
-templ filterForm(f Filter) {
+// pasteForm lets a connected user summarize any YouTube video by pasting its URL
+// (Feature 2). The result (a video card, or an inline error) swaps into
+// #paste-result; the next list refresh shows it inline. Summarization runs
+// through the shared caption rate gate like every other fetch.
+templ pasteForm() {
+	<form
+		class="paste"
+		method="post"
+		action="/paste"
+		hx-post="/paste"
+		hx-target="#paste-result"
+		hx-swap="innerHTML"
+	>
+		<label>
+			Summarize any video
+			<input type="url" name="url" placeholder="Paste a YouTube link…" required/>
+		</label>
+		<button type="submit">Add</button>
+	</form>
+	<div id="paste-result"></div>
+}
+
+templ filterForm(f Filter, channels []string) {
 	<form
 		class="filters"
 		method="get"
@@ -153,7 +187,16 @@ templ filterForm(f Filter) {
 		hx-swap="innerHTML"
 		hx-indicator="#filter-indicator"
 	>
-		<label>Channel <input type="text" name="channel" value={ f.Channel } placeholder="any"/></label>
+		if len(channels) > 0 {
+			<label>
+				Channels
+				<select name="channel" multiple size="4">
+					for _, c := range channels {
+						<option value={ c } selected?={ f.HasChannel(c) }>{ c }</option>
+					}
+				</select>
+			</label>
+		}
 		<label class="filter-check">
 			<input type="checkbox" name="summarized" value="1" if f.OnlySummarized { checked }/>
 			Summarized only
@@ -169,12 +212,16 @@ templ filterForm(f Filter) {
 // and a single disclosure holding the older un-summarized back-catalogue. Cards
 // reflow to a single column on mobile; an empty list shows a friendly first-run
 // state instead of a blank table.
-templ summaryList(b listBuckets, hasConnected bool) {
+templ summaryList(b listBuckets, hasConnected bool, autoSummarize bool) {
 	if b.empty() {
 		if hasConnected {
 			<div class="empty empty-connected">
 				<strong>Your account is connected</strong>
-				<span>Tapir is finding your subscriptions and fetching captions — summaries appear here gradually. Check back later.</span>
+				if autoSummarize {
+					<span>Tapir is finding your subscriptions and fetching captions — summaries appear here gradually. Check back later.</span>
+				} else {
+					<span>Tapir is finding your subscriptions. You are in Manual mode, so videos appear here with a Summarize button — pick the ones you want, or switch to Automatic in your account.</span>
+				}
 			</div>
 		} else {
 			<div class="empty">

test/acceptance/scenario_coverage_test.go

@@ -26,10 +26,11 @@ import (
 // longer matches a real non-pending scenario.
 var scenarioCoverage = map[string]string{
 	// ai_routing.feature
-	"Local AI produces the summary":                             "TestSummarize_LocalSucceeds",
+	"Local AI produces the summary":                                     "TestSummarize_LocalSucceeds",
-	"Local AI fails and the user has a BYO provider configured": "TestSummarize_FallsBackToBYO",
+	"Local AI fails and the user has a BYO provider configured":         "TestSummarize_FallsBackToBYO",
-	"Local AI fails and the user has no BYO provider":           "TestSummarize_LocalFailsNoBYO_NoExternalSend",
+	"Local AI fails and the user has no BYO provider":                   "TestSummarize_LocalFailsNoBYO_NoExternalSend",
-	"A user without BYO never has content sent externally":      "TestSummarize_NoBYO_ContentOnlyLocal",
+	"A user without BYO never has content sent externally":              "TestSummarize_NoBYO_ContentOnlyLocal",
+	"A model returns unparseable output and the next endpoint succeeds": "TestSummarize_FallsBackOnMalformedOutput",
 
 	// landing_page.feature
 	"An unauthenticated visit to the root is sent to the welcome page":    "TestUnauthenticatedRootRedirectsToWelcome",
@@ -37,9 +38,16 @@ var scenarioCoverage = map[string]string{
 	"An authenticated user on the welcome page sees their way in and out": "TestWelcomeLoggedIn",
 
 	// connect_account.feature
-	"Connect a YouTube account":                              "TestCallbackExchangesAndRecordsConnection",
+	"Connect a YouTube account":                          "TestCallbackExchangesAndRecordsConnection",
-	"Connecting an account discovers videos immediately":     "TestCallbackTriggersDiscovery",
+	"Connecting an account discovers videos immediately": "TestCallbackTriggersDiscovery",
-	"Tokens are never stored in the clear":                   "TestCallbackExchangesAndRecordsConnection",
+	"Connecting summarizes my newest videos right away":  "TestNewestUnsummarizedVideoIDs",
+	"Tokens are never stored in the clear":               "TestCallbackExchangesAndRecordsConnection",
+
+	// paste_url.feature
+	"Paste a valid YouTube URL":                              "TestPasteValidURLAddsAndRequests",
+	"Pasting an invalid link is rejected":                    "TestPasteInvalidURLRejected",
+	"Pasting a video that cannot be found is honest":         "TestPasteVideoNotFound",
+	"Pasting the same video twice does not duplicate it":     "TestPasteDedupNoDuplicate",
 	"Revoking a connection stops watching but keeps history": "TestDisconnectRemovesTokenAndConnectionKeepsAccount",
 
 	// summarize_mode.feature
@@ -60,6 +68,7 @@ var scenarioCoverage = map[string]string{
 	"A subscribed channel posts a video with no usable transcript": "TestVideoWithNoTranscriptIsSkipped",
 	"A channel I am not subscribed to posts a video":               "TestUnsubscribedChannelVideoIsNotProcessed",
 	"The same video is not summarized twice":                       "TestAlreadySummarizedVideoIsNotReprocessed",
+	"Re-analyzing a stored video does not re-fetch its transcript": "TestProcessNewVideo_SecondSummarizeDoesNotRefetch",
 }
 
 var (