docs: add ADR-017 (Dex-write invite flow) retroactively; annotate ADR-002/013/014

Reconciliation pass after parallel agent sessions shipped v0.6.0/v0.7.0.

ADR-017 documents the v0.7.0 invite flow, which gave Tapir scoped create+get on
passwords.dex.coreos.com in the auth namespace — Tapir now WRITES to the shared
identity provider. This shipped with no ADR; recorded retroactively with the
principle-reversal named (partially supersedes ADR-002/013), the security analysis
(bounded RBAC, but a real larger trust surface), and the open gaps (orphaned Dex
accounts on delete; plaintext invite tokens). Cross-referenced in ADR-002 and
ADR-013 status lines so a future reader isn't misled.

ADR-014 annotated: 429 handling shipped in v0.6.0 but decision item 2 (shared
per-egress-IP rate gate) appears realised as per-VIDEO backoff, not a process-wide
IP gate — flagged not-confirmed-done. Also flags the missing migration 008 /
rate_limited_at discrepancy (v0.6.0 report cited 008; tree jumps 007->009).

No code changed in this commit — audit trail only.

DECISIONS.md

@@ -29,7 +29,9 @@ Go's concurrency model fits the watcher/worker shape).
 
 ## ADR-002 — No Supabase; reuse existing Dex / ESO / Postgres conventions
 
-**Status:** Accepted (2026-06-02)
+**Status:** Accepted (2026-06-02). The "Tapir does not write to the shared identity provider"
+implication is **partially superseded by ADR-017** (invite flow writes Dex Password CRs); the
+no-Supabase / reuse-existing-primitives decision stands.
 
 **Context.** The draft proposed self-hosted Supabase for auth + RLS + secrets (Vault). The
 homelab already runs **Dex** (OIDC), **ESO + 1Password** (secrets), and a **postgres18**
@@ -292,7 +294,11 @@ explicit call, with isolation as the guardrail that keeps it safe.
 
 ## ADR-013 — Account deletion is Tapir-side only; the Dex identity is left intact
 
-**Status:** Accepted (2026-06-03)
+**Status:** Accepted (2026-06-03). The "Tapir never holds write access to the shared identity
+provider" rationale is **partially superseded by ADR-017** (the invite flow now *creates* Dex
+Password CRs). The deletion-behaviour decision itself — delete Tapir-side state, leave the Dex
+identity intact — still stands; ADR-017 only changes the create side, not delete. See ADR-017
+for the now-asymmetric posture (Tapir can create Dex accounts but still does not delete them).
 
 **Context.** Stage 1 (ADR-012) added account deletion. A registered user is two things: a
 `users` row (plus all their data, cascade-linked) in Tapir's Postgres, and a subject identity
@@ -308,7 +314,9 @@ deprovision the Dex identity. The maintainer chose (a).
 - All of that user's secrets in the SecretStore (the per-user YouTube refresh-token refs).
 
 The **Dex identity is deliberately left intact.** Tapir does not deprovision, disable, or
-modify the shared Dex directory.
+modify the shared Dex directory **on deletion**. (Note per ADR-017: Tapir *does* now create Dex
+Password CRs on invite — so the create and delete sides are deliberately asymmetric, and a
+deleted user's Dex Password CR persists. See ADR-017 consequences.)
 
 **Consequences.**
 - **Clean re-registration:** a deleted user who logs in again arrives as a Dex-authenticated
@@ -319,9 +327,13 @@ modify the shared Dex directory.
   the identity carries no Tapir content. **But if Tapir ever moves toward Future C (real
   external/public users), this is a GDPR-shaped gap** — a true "delete my account" there must
   also deprovision or anonymise the Dex identity, which is a new ADR and likely a Dex-admin
-  integration Tapir does not currently have.
-- **Blast radius stays small:** Tapir never holds write access to the shared identity provider,
-  consistent with the estate's blast-radius-minimisation posture (ADR-002, architecture review).
+  integration Tapir does not currently have. **ADR-017 widens this gap:** Tapir now *creates*
+  the Dex Password CR but does not delete it, so a deleted Tapir user leaves an orphaned Dex
+  local-password account. Tracked as a known gap in ADR-017.
+- **Blast radius:** ADR-013 originally claimed "Tapir never holds write access to the shared
+  identity provider." **ADR-017 changes this** — Tapir now holds scoped `create`+`get` on
+  `passwords.dex.coreos.com` in the `auth` namespace. The blast radius is no longer zero; it is
+  bounded by that RBAC. See ADR-017 for the security analysis.
 
 **Reversibility.** Adding Dex deprovisioning later is a superseding ADR; nothing about the
 current choice blocks it. Recorded now because "deletion is partial by design" is a deliberate
@@ -331,7 +343,9 @@ semantic that future-Tapir (and any compliance review) must know was chosen, not
 
 ## ADR-014 — Timedtext 429 handling: per-host backoff + honest in-flight UX, before any Whisper reconsideration
 
-**Status:** Accepted (2026-06-03)
+**Status:** Accepted (2026-06-03). **Partially implemented as of v0.6.0** — see the
+implementation note at the end; the shared per-egress-IP rate gate (decision item 2) may not be
+fully realised. Verify against `internal/runner` + the youtube adapter before treating as done.
 
 **Context.** ADR-010 acquires captions from the unauthenticated `timedtext` baseUrl. Live runs
 show that endpoint **rate-limits per source IP (HTTP 429) under volume** — many videos fetched
@@ -386,6 +400,19 @@ clean data then tells you whether Whisper is warranted.
 dedicated egress IP / outbound proxy is worth it; CronJob-driven `tapir run` interaction with
 the rate gate (the batch path moves into k3s per the deferred CronJob item).
 
+**Implementation note (2026-06-03, v0.6.0 — added during reconciliation).** A v0.6.0 release
+shipped 429 handling: `domain.SourceRateLimited` (429 no longer collapsed to `SourceNone`),
+youtube adapter maps 429 → `SourceRateLimited`, migration 007 `transcript_status` + (per the
+v0.6.0 report) a `videos.rate_limited_at` column, `TAPIR_FETCH_BACKOFF` config, runner records
+rate-limited + skips within the backoff window, and a "⏳ Retrying later" badge. This realises
+decision items 1, 3, and 4 well. **Item 2 (a single shared per-egress-IP rate gate) appears to
+be realised as per-*video* backoff state, NOT a process-wide IP gate** — multiple videos can
+still each hit the endpoint and collectively trip the per-IP 429. Treat item 2 as **not yet
+confirmed done**; verify in `internal/runner`/youtube adapter and, if absent, it remains open.
+ALSO: the v0.6.0 report referenced "migration 008 videos.rate_limited_at" but **no migration 008
+exists on `main`** (tree jumps 007→009). Resolve whether `rate_limited_at` actually shipped (in
+007? lost? renumbered?) — a documentation/build discrepancy flagged during reconciliation.
+
 ---
 
 ## ADR-015 — Per-user credentials: envelope-encrypted in PG18, not vault-stored
@@ -489,6 +516,82 @@ about editing a gate while it's unmet) so the reasoning survives, not just the n
 
 ---
 
+## ADR-017 — Invite flow: Tapir creates Dex local-password accounts (write access to the shared identity provider)
+
+**Status:** Accepted (2026-06-03), **recorded retroactively during reconciliation.** This
+capability **shipped in v0.7.0 without an ADR** — code, RBAC, and a deployed ServiceAccount
+landed before any decision record existed. This ADR documents what shipped and honestly records
+that the decision-before-code discipline was not followed here (see "Process note"). **Partially
+supersedes ADR-002 and ADR-013** (the "Tapir holds no write access to the shared identity
+provider" posture).
+
+**Context.** Stage 1 onboarding needs a way for a friend to get a login. Two paths shipped:
+Google OIDC via Dex (no Tapir code — Dex handles it), and an **invite flow** where Tapir itself
+provisions a Dex **local-password** account. The invite flow is what this ADR is about.
+
+**What shipped (reconstructed from `internal/adapters/dex/dex.go`, `internal/web/invite.go`,
+migration `009_invitations`).**
+1. `tapir invite <email>` (host CLI) writes an `invitations` row: a 32-byte crypto-random,
+   single-use, 7-day-expiry `token` (the token is the capability), `email`, `used_at`.
+   The `invitations` table is deliberately **not** RLS/`user_id`-scoped — the invitee has no
+   user yet and the token itself is the secret. (Sound; documented in the migration.)
+2. Recipient visits `/invite/{token}` (public, no session), sets a password (validated *before*
+   the token is consumed, so a typo doesn't burn it), the token is claimed exactly once.
+3. Tapir bcrypt-hashes (cost 12) and **POSTs a `passwords.dex.coreos.com` Custom Resource into
+   the `auth` namespace** via the in-cluster Kubernetes API, authenticating as the `tapir`
+   ServiceAccount. TLS validated against the mounted cluster CA. Off-cluster (dev) it returns
+   `ErrNotInCluster` and degrades without consuming the invite.
+4. RBAC applied this deploy: the `tapir` ServiceAccount has **`create`+`get` on
+   `passwords.dex.coreos.com` in the `auth` namespace** (and only that).
+5. Dex (kubernetes storage) then serves local-password login for that email; Tapir's
+   registration gate creates the profile on first login.
+
+**Decision (as ratified now).** Accept the invite flow as built: Tapir *may* hold scoped write
+access to Dex's `passwords` resource in the `auth` namespace, for the purpose of invite-based
+local-account creation. This is a deliberate, bounded reversal of the prior "no write access to
+the shared identity provider" posture (ADR-002/013).
+
+**Why this is acceptable (the case for keeping it).**
+- The RBAC is **minimally scoped**: `create`+`get` on one resource type in one namespace, not
+  broad Dex/cluster write. Blast radius is bounded and inspectable.
+- It enables friend onboarding **without Google OAuth app verification** (ADR-008 deferred that),
+  which is genuinely useful for Future B.
+- The code is careful: validate-before-consume, single-use tokens, graceful off-cluster degrade,
+  sentinel errors mapped to clear messages, the base64-bcrypt storage gotcha handled.
+
+**Consequences / known gaps (the case to watch).**
+- **Reverses a load-bearing principle.** ADR-002 and ADR-013 leaned on "Tapir never writes to the
+  shared identity provider" for blast-radius minimisation. That is no longer true. Anyone reading
+  those ADRs without this one would be misled — hence the cross-references added to both.
+- **Create/delete asymmetry → orphaned Dex accounts.** Tapir now *creates* Dex Password CRs but
+  (per ADR-013) does not *delete* them on account deletion. A deleted Tapir user leaves an
+  orphaned Dex local-password account that can still authenticate (though it would hit the
+  registration gate with no profile). This widens the ADR-013 right-to-erasure gap. **Open.**
+- **`create` on a shared-namespace identity resource** is a meaningfully larger trust surface than
+  the rest of Tapir. If the `tapir` pod is compromised, the attacker can mint Dex local accounts.
+  Bounded by the namespace/resource scope, but real — worth a deliberate look before Future C.
+- Token custody for invites is in PG (`invitations.token`) in plaintext; single-use + 7-day TTL
+  bound the exposure, but a DB read yields live invite tokens until claimed/expired.
+
+**Process note (why this ADR is retroactive).** This capability was built and deployed by
+parallel agent sessions while the main planning thread was elsewhere, and shipped with no ADR —
+the first time in this project a guardrail-reversing change skipped the decision-before-code
+discipline. Recorded here not to rubber-stamp it but to restore the audit trail: the decision is
+now visible, its principle-reversal is named, and its open gaps (orphaned accounts, the larger
+trust surface) are tracked rather than buried in a release note. The maintainer is ratifying it
+after the fact; if on reflection the trust surface is unwanted, reversing it (drop the RBAC +
+invite flow, rely on Google OIDC only) is a clean follow-up ADR.
+
+**Open items this ADR creates:**
+- Decide whether to close the orphaned-Dex-account gap (delete the Password CR on account
+  deletion — but that *widens* write access to `delete`, the opposite direction; or accept the
+  orphan for Future B and fix at Future C).
+- Confirm the RBAC really is `create`+`get` only (not broader) against the deployed manifest in
+  `infra`.
+- Review the larger trust surface before any Future C move.
+
+---
+
 ## Rejected alternatives
 
 Approaches considered during the 2026-06-02 planning + grill session and **deliberately not