docs: merge codex insights into claude super plan

Adds key architectural choices summary, assumptions section,
sidebar visual demotion (F9), message click-to-expand in compact
log, and backend-first rationale from the codex plan.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

docs/cockpit/2026-04-01-msp-assistant-harness-plan-claude.md

@@ -11,6 +11,17 @@ Reframe `/assistant` from a generic AI chat surface into a **live MSP triage coc
 
 The change is a UI and data layer reframe. The existing session, branching, PSA, and conclude architecture is preserved and extended, not rebuilt.
 
+### Key Architectural Choices
+
+This plan explicitly chooses:
+
+- **`FlowPilot`** as the primary page/product label (not "Assistant Harness")
+- **Backend triage + handoff contracts required in v1** — not deferred to a later phase
+- **Desktop-first cockpit layout** with clean mobile degradation
+- **Explicit persisted triage fields** on the session model, not purely derived/computed header state
+- **Prompt-embedded structured extraction** (`[TRIAGE_UPDATE]` marker) as the primary AI triage path, with post-response model pass only as fallback
+- **Sidebar visual demotion** — existing sidebar stays but is visually de-emphasized so the cockpit reads as an operations surface, not a chat app
+
 ---
 
 ## What Phase 0 Resolved
@@ -272,7 +283,7 @@ Thin handle bar between work zone and conversation log. On drag: update `workZon
 
 ### F7 — Compact `ConversationLog` rendering
 
-Replace current full `<ChatMessage>` bubbles in the log zone with a compact list: `you: ...` / `fp: ...` prefix style, tighter line height, no avatars. `ChatMessage` can still be used for rich content (forks, suggested flows) in a compact variant.
+Replace current full `<ChatMessage>` bubbles in the log zone with a compact list: `you: ...` / `fp: ...` prefix style, tighter line height, no avatars. `ChatMessage` can still be used for rich content (forks, suggested flows) in a compact variant. Individual messages should support click-to-expand for full rendering when the engineer needs to re-read a longer response or review a suggested flow.
 
 ### F8 — Redesigned `ConcludeSessionModal.tsx`
 
@@ -283,7 +294,16 @@ On open:
 4. Render output destination checkboxes: Post to CW note / Save to KB / Send client summary
 5. Confirm → call resolve/escalate/pause with enriched request body including structured fields
 
-### F9 — MSP-native language pass
+### F9 — Sidebar visual demotion
+
+The existing `ChatSidebar` stays functionally unchanged but should be visually softened so the cockpit — not the session list — reads as the primary surface. Specific changes:
+
+- Reduce sidebar background contrast (use `bg-sidebar` or one step darker)
+- Reduce sidebar header prominence (smaller label, no bold "Chat History" heading)
+- Rename "Chat History" → "Case History" (part of language pass)
+- Default sidebar to collapsed state on first cockpit load (existing collapse toggle + `localStorage`)
+
+### F10 — MSP-native language pass
 
 | Old | New |
 |-----|-----|
@@ -295,14 +315,14 @@ On open:
 | "Chat history" (sidebar label) | "Case History" |
 | Compose placeholder | "Describe finding, paste log output, or ask FlowPilot..." |
 
-### F10 — New API methods (`aiSessions.ts`)
+### F11 — New API methods (`aiSessions.ts`)
 
 ```typescript
 updateTriage(sessionId: string, fields: Partial<TriageMeta>): Promise<TriageMeta>
 getHandoffDraft(sessionId: string): AsyncGenerator<HandoffDraftChunk>
 ```
 
-### F11 — New types (`types/ai-session.ts`)
+### F12 — New types (`types/ai-session.ts`)
 
 ```typescript
 interface TriageMeta {
@@ -333,6 +353,9 @@ interface QuestionItem {
 ## Phased Execution Order
 
 ### Phase 1 — Backend Foundation
+
+> Lock backend schema and API changes first so the cockpit can be built against stable session contracts.
+
 1. Write migration `071` — add 5 columns to `ai_sessions`
 2. Run `alembic upgrade head`, verify columns
 3. Update `AISession` model with new mapped columns
@@ -368,18 +391,19 @@ interface QuestionItem {
 25. Implement drag-resizable split with `localStorage` persistence
 26. Compact `ConversationLog` rendering
 
-### Phase 6 — Handoff Modal + Language Pass
+### Phase 6 — Handoff Modal + Language Pass + Sidebar
 27. Redesign `ConcludeSessionModal.tsx` — structured handoff form
-28. MSP-native language pass across all assistant components
+28. Sidebar visual demotion — background, label prominence, default-collapsed
-29. Update `<PageMeta>` title
+29. MSP-native language pass across all assistant components
+30. Update `<PageMeta>` title
 
 ### Phase 7 — QA + Hardening
-30. `npx tsc -b` — fix any TypeScript errors
+31. `npx tsc -b` — fix any TypeScript errors
-31. `npm run build` — production build clean
+32. `npm run build` — production build clean
-32. Functional regression: all chat flows, session switching, conclude/resume
+33. Functional regression: all chat flows, session switching, conclude/resume
-33. Harness feel test: cockpit within 3 seconds?
+34. Harness feel test: cockpit within 3 seconds?
-34. Mobile viewport check
+35. Mobile viewport check
-35. Stress test: 50+ messages, 10+ steps, long outputs
+36. Stress test: 50+ messages, 10+ steps, long outputs
 
 ---
 
@@ -450,6 +474,18 @@ curl -X POST http://localhost:8000/ai-sessions/{id}/handoff-draft \
 
 ---
 
+## Assumptions
+
+- Desktop is the primary target; mobile must remain usable but does not drive the layout.
+- `/assistant` remains the chat-session cockpit; `/pilot` is out of scope.
+- New triage fields are **additive** — they do not replace `problem_summary`, `problem_domain`, `ticket_data`, or `conversation_messages`.
+- `issue_category` is the operator-facing display field; `problem_domain` remains the internal classifier. Both coexist.
+- `evidence_items` is editable by both AI and engineer; engineer edits persist through the triage PATCH endpoint.
+- PSA context is optional — every triage header field must degrade gracefully when PSA is absent or session is free-text-only.
+- The existing `TaskLane.tsx` component remains in the codebase — `StepsPanel` is a new component that consumes the same props with different rendering. No risky renames during this work.
+
+---
+
 ## Critical Files
 
 | File | Change |