refactor(web): dock chat inline below the summary, integrated view (ADR-027)

The chat was a separate page — opening it left the summary behind, the very
context you're asking about. Now the chat docks open IN PLACE below the summary:
"Dig deeper" reveals the chat section (HTMX, outerHTML over the closed dock) so
the summary stays on screen above it; no navigation. The no-JS fallback renders
the full summary AND the open chat on one page (the same integrated view), so
progressive enhancement holds.

Extracts a shared summaryBody templ so the detail page and the chat page render
one identical summary, not two divergent ones. GET /v/{id}/chat returns just the
open chat section as a fragment for the inline reveal, or the full summary+chat
page for a no-JS navigation; POST swaps the panel inline or re-renders the whole
page. Tests assert summary+chat coexist on the page and the reveal is a fragment.

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

docs/use-cases/chat_transcript.feature

@@ -14,6 +14,12 @@ Feature: Chat with a video's stored transcript
   Scenario: A summary view offers a deeper-dive into the video
     When I view the summary
     Then I see a "dig deeper" affordance that opens a chat about this video
+    And it opens the chat in place, below the summary, without leaving the page
+
+  Scenario: The summary and the chat are on one page
+    When I open the chat
+    Then the summary stays visible alongside the chat
+    And I can read the summary while I ask questions
 
   Scenario: Ask a question answered from the stored transcript
     When I ask a question in the chat

internal/web/chat.go

@@ -64,13 +64,21 @@ func (a *App) handleChat(w http.ResponseWriter, r *http.Request) {
 	if !ok {
 		return
 	}
-	a.render(w, r, ChatPage(chatView{
+	view := chatView{
 		VideoID:   row.VideoID,
 		Title:     displayTitle(*row),
 		Available: hasText,
 		Models:    a.Chat.Models(),
 		Selected:  a.Chat.DefaultModel(row.AIModel),
-	}))
+	}
+	// HTMX (the in-place reveal from the summary) gets just the open chat section,
+	// swapped over the closed dock so the summary above it stays put. A no-JS
+	// navigation gets the full page: the whole summary plus the open chat.
+	if isHTMX(r) {
+		a.render(w, r, chatSection(view))
+		return
+	}
+	a.render(w, r, ChatPage(*row, view))
 }
 
 // handleChatMessage answers one question against the stored transcript (POST).
@@ -129,7 +137,7 @@ func (a *App) handleChatMessage(w http.ResponseWriter, r *http.Request) {
 			view.Truncated = reply.Truncated
 		}
 	}
-	a.renderChat(w, r, view)
+	a.renderChatTurn(w, r, *row, view)
 }
 
 // loadOwnedSummary fetches the summary for the path's video scoped to userID, or
@@ -166,14 +174,15 @@ func (a *App) readTranscript(w http.ResponseWriter, r *http.Request, row store.S
 	return t.Content, true, true
 }
 
-// renderChat returns the chat panel fragment for an HTMX request, or the full
-// chat page otherwise (no-JS POST re-renders the whole page).
-func (a *App) renderChat(w http.ResponseWriter, r *http.Request, v chatView) {
+// renderChatTurn returns the chat panel fragment for an HTMX answer (swapped in
+// place within the open dock), or the full chat page otherwise — the no-JS POST
+// re-renders the whole summary + open chat with the new turn.
+func (a *App) renderChatTurn(w http.ResponseWriter, r *http.Request, row store.SummaryRow, v chatView) {
 	if isHTMX(r) {
 		a.render(w, r, chatPanel(v))
 		return
 	}
-	a.render(w, r, ChatPage(v))
+	a.render(w, r, ChatPage(row, v))
 }
 
 // resolveModel keeps the posted model only when it is an offered option; anything

internal/web/chat_handler_test.go

@@ -137,6 +137,8 @@ func TestChatEntryAffordanceOnSummaryView(t *testing.T) {
 	html := body(t, do(t, withChat, httptest.NewRequest(http.MethodGet, "/v/"+videoX, nil)))
 	require.Contains(t, html, "Dig deeper", "the deeper-dive affordance is shown when chat is enabled")
 	require.Contains(t, html, "/v/"+videoX+"/chat", "it links to this video's chat")
+	require.Contains(t, html, `id="chat-section"`, "the dock lives on the detail page")
+	require.Contains(t, html, `hx-get="/v/`+videoX+`/chat"`, "it opens the chat in place (HTMX), not a navigation")
 
 	// With no chat backend wired the affordance is absent (routes unmounted).
 	noChat := newApp(t)
@@ -145,6 +147,39 @@ func TestChatEntryAffordanceOnSummaryView(t *testing.T) {
 	require.NotContains(t, html, "Dig deeper", "no affordance when chat is disabled")
 }
 
+// The summary and the chat live together (the integrated UX): the no-JS chat page
+// renders the full summary alongside the chat, and the HTMX reveal returns just
+// the open chat section as a fragment so it docks in below the summary already on
+// screen — the summary is never navigated away from.
+func TestChatIntegratedWithSummaryOnSamePage(t *testing.T) {
+	ctx := context.Background()
+	chatter := &fakeChatter{models: []string{"phi4-mini", "gemma4-26b"}}
+	app := newChatApp(t, chatter, nil)
+	p := rawPool(t)
+	resetDB(t, p)
+	require.NoError(t, deliver(ctx, app, videoX, "SUMMARY-BODY-MARKER"))
+	seedVideo(t, p, videoX, "X Title", "https://x", time.Time{})
+	seedTranscript(t, app.Store.(*store.Store), videoX, "the transcript")
+
+	// No-JS full page: the summary payload and the chat are on one page.
+	html := body(t, getChat(t, app, videoX))
+	require.Contains(t, html, "SUMMARY-BODY-MARKER", "the summary text is shown on the chat page")
+	require.Contains(t, html, "takeaway one", "takeaways shown alongside the chat")
+	require.Contains(t, html, "highlight one", "highlights shown alongside the chat")
+	require.Contains(t, html, "Ask about this video", "the chat sits on the same page as the summary")
+	require.Contains(t, html, `name="question"`, "the ask form is present")
+
+	// HTMX reveal: the open chat section ONLY (a fragment) — no full-page chrome and
+	// no duplicated summary, so it swaps in below the summary already rendered.
+	req := httptest.NewRequest(http.MethodGet, "/v/"+videoX+"/chat", nil)
+	req.Header.Set("HX-Request", "true")
+	frag := body(t, do(t, app, req))
+	require.NotContains(t, frag, "<html", "the reveal is a fragment, not a full page")
+	require.NotContains(t, frag, "SUMMARY-BODY-MARKER", "the reveal does not re-send the summary (it's already on screen)")
+	require.Contains(t, frag, `id="chat-section"`, "the fragment replaces the dock in place")
+	require.Contains(t, frag, `name="question"`, "the ask form is in the revealed section")
+}
+
 // THE KEY SAFETY ASSERTION (ADR-027): a chat answer is produced entirely from the
 // stored transcript — the model receives the stored text, and neither the
 // summarize→fetch path nor the YouTube fetch path is ever touched. The tripwire

internal/web/view.go

@@ -731,9 +731,11 @@ a.btn, a.btn:visited { color: var(--accent-fg); }
 .detail ul { margin: 0; padding-left: 1.2rem; line-height: 1.6; }
 .detail li { margin-bottom: var(--s1); }
 
-/* deeper-dive chat (ADR-027) */
-.dig-deeper { margin: var(--s3) 0 0; }
-.chat .chat-scope { margin: 0 0 var(--s4); font-size: .9rem; }
+/* deeper-dive chat (ADR-027) — docks in place below the summary */
+.chat-dock { margin-top: var(--s5); border-top: 1px solid var(--line); padding-top: var(--s4); }
+.chat-dock .chat-open { display: inline-block; }
+.chat-heading { font-size: 1.1rem; margin: 0 0 var(--s2); }
+.chat-scope { margin: 0 0 var(--s3); font-size: .9rem; }
 .chat-panel { display: flex; flex-direction: column; gap: var(--s3); }
 .chat-log { display: flex; flex-direction: column; gap: var(--s3); }
 .chat-turn { border-radius: var(--radius); padding: var(--s2) var(--s3); }

internal/web/views.templ

@@ -410,14 +410,11 @@ templ noCaptionsCard(r store.SummaryRow) {
 	</li>
 }
 
-// DetailPage is the full summary view: text, highlights, takeaways, metadata,
-// and the action button group. chatEnabled adds the "dig deeper" affordance
-// (ADR-027) — a quiet link into the per-video chat over the stored transcript.
-templ DetailPage(r store.SummaryRow, chatEnabled bool) {
-	@Layout("Tapir — " + displayTitle(r)) {
-		<article class="detail">
-			<p class="back"><a href="/">← Summaries</a></p>
-			<h1>{ displayTitle(r) }</h1>
+// summaryBody is the summary payload shared by the detail page and the no-JS
+// chat page (so the chat page shows the same summary, not a separate view):
+// metadata, embed, source, the action toggles, then the attention-saving order
+// Takeaways → Highlights → Summary (UX review A8).
+templ summaryBody(r store.SummaryRow) {
 	<p class="meta">
 		if detailMeta(r) != "" {
 			<span>{ detailMeta(r) }</span>
@@ -441,16 +438,7 @@ templ DetailPage(r store.SummaryRow, chatEnabled bool) {
 	if r.URL != "" {
 		<p class="source"><a href={ externalURL(r.URL) } rel="noopener noreferrer">watch on source ↗</a></p>
 	}
-			if chatEnabled {
-				// Where the "I want more" reaction goes (ADR-027). A quiet link, not a
-				// loud CTA — it deepens value for a reader already here, never nudges.
-				<p class="dig-deeper"><a class="btn-secondary" href={ chatURL(r.VideoID) }>Dig deeper — ask about this video →</a></p>
-			}
 	@ActionButtons(r.VideoID, actionSet(r.Actions))
-			// Lead with the attention-saving payload: Takeaways ("is this worth my
-			// time?") first, then Highlights, then the full Summary last (UX review
-			// A8). Takeaways/Highlights are conditional, so a video without them falls
-			// through to the Summary leading naturally.
 	if len(r.Takeaways) > 0 {
 		<section>
 			<h2>Takeaways</h2>
@@ -475,21 +463,65 @@ templ DetailPage(r store.SummaryRow, chatEnabled bool) {
 		<h2>Summary</h2>
 		<p class="body">{ r.Summary }</p>
 	</section>
+}
+
+// DetailPage is the full summary view: the summary payload, then (when chat is
+// enabled) the deeper-dive dock (ADR-027) — a reveal that opens the chat IN PLACE
+// below the summary, so the summary stays on screen as the context being asked
+// about rather than being navigated away from.
+templ DetailPage(r store.SummaryRow, chatEnabled bool) {
+	@Layout("Tapir — " + displayTitle(r)) {
+		<article class="detail">
+			<p class="back"><a href="/">← Summaries</a></p>
+			<h1>{ displayTitle(r) }</h1>
+			@summaryBody(r)
+			if chatEnabled {
+				@chatReveal(r.VideoID)
+			}
 		</article>
 	}
 }
 
-// ChatPage is the per-video deeper-dive chat (ADR-027): a question/answer surface
-// over the video's ALREADY-STORED transcript. The back link returns to the
-// summary it was entered from. All the interaction lives in chatPanel so the HTMX
-// answer-swap and the no-JS full-page render share one component.
-templ ChatPage(v chatView) {
-	@Layout("Tapir — Ask — " + v.Title) {
-		<article class="detail chat">
-			<p class="back"><a href={ videoURL(v.VideoID) }>← { v.Title }</a></p>
-			<h1>Ask about this video</h1>
+// chatReveal is the CLOSED dock at the foot of the summary: a quiet affordance,
+// not a loud CTA (it deepens value for a reader already here, never nudges). With
+// JS it swaps itself for the open chat section in place (HTMX, summary stays
+// above); without JS the same href navigates to the full chat page, which renders
+// the summary alongside the chat. Either way the summary is never lost.
+templ chatReveal(videoID string) {
+	<section id="chat-section" class="chat-dock">
+		<a
+			class="btn-secondary chat-open"
+			href={ chatURL(videoID) }
+			hx-get={ string(chatURL(videoID)) }
+			hx-target="#chat-section"
+			hx-swap="outerHTML"
+		>
+			Dig deeper — ask about this video →
+		</a>
+	</section>
+}
+
+// chatSection is the OPEN dock: heading + scope note + the chat panel, swapped in
+// over the closed reveal (same #chat-section id, outerHTML). It is the HTMX reveal
+// response AND the inline chat block on the no-JS chat page.
+templ chatSection(v chatView) {
+	<section id="chat-section" class="chat-dock chat-dock-open">
+		<h2 class="chat-heading">Ask about this video</h2>
 		<p class="chat-scope muted">Answers come only from this video's stored transcript — Tapir never fetches anything new here.</p>
 		@chatPanel(v)
+	</section>
+}
+
+// ChatPage is the no-JS full-page render of the chat: the whole summary followed
+// by the open chat dock, so a visitor without JS sees the same integrated view
+// (summary beside the conversation) that JS users get inline via the reveal.
+templ ChatPage(r store.SummaryRow, v chatView) {
+	@Layout("Tapir — " + displayTitle(r)) {
+		<article class="detail">
+			<p class="back"><a href="/">← Summaries</a></p>
+			<h1>{ displayTitle(r) }</h1>
+			@summaryBody(r)
+			@chatSection(v)
 		</article>
 	}
 }

test/acceptance/scenario_coverage_test.go

@@ -65,6 +65,7 @@ var scenarioCoverage = map[string]string{
 
 	// chat_transcript.feature (ADR-027)
 	"A summary view offers a deeper-dive into the video":         "TestChatEntryAffordanceOnSummaryView",
+	"The summary and the chat are on one page":                   "TestChatIntegratedWithSummaryOnSamePage",
 	"Ask a question answered from the stored transcript":         "TestChatAnswersFromStoredTranscriptWithoutAnyFetch",
 	"Chat never fetches captions or reaches YouTube":             "TestChatAnswersFromStoredTranscriptWithoutAnyFetch",
 	"A video with no stored transcript offers no chat":           "TestChatUnavailableWhenNoStoredTranscript",