docs(21-06): complete chat search and Cmd+K gap closure plan

- Add 21-06-SUMMARY.md documenting search filtering and keyboard shortcut
- Advance STATE.md to ready_for_verification, 100% progress
- ROADMAP.md phase 21 marked Complete (7/7 summaries)

.planning/ROADMAP.md

@@ -10,7 +10,7 @@
 
 ## Phases
 
-- [ ] **Phase 21: Chat Foundation** — Persistent conversation storage, sidebar, CRUD, markdown rendering, theme integration, keyboard shortcuts
+- [x] **Phase 21: Chat Foundation** — Persistent conversation storage, sidebar, CRUD, markdown rendering, theme integration, keyboard shortcuts (completed 2026-04-01)
 - [ ] **Phase 22: Agent Streaming** — Real-time streaming via SSE/WebSocket, agent selector, agent identity on messages, stop/edit/regenerate, slash commands and @mentions
 - [ ] **Phase 23: Brainstormer Flow** — Brainstormer agent persona, structured questioning flow, spec generation, PM handoff, task creation from chat, agent status updates in chat
 - [ ] **Phase 24: Search, History & Branching** — Full-text search across all conversations, export, conversation branching, message bookmarks
@@ -31,7 +31,7 @@
   3. Agent messages render with full markdown: code blocks with syntax highlighting and a copy button, tables, lists, headings, links, and inline images
   4. Conversations and all messages are stored in libSQL and survive a server restart
   5. The chat interface applies Catppuccin Mocha, Tokyo Night, and Catppuccin Latte themes correctly; code block highlighting matches the active theme
-**Plans:** 7 plans (6 complete + 1 gap closure)
+**Plans:** 7/7 plans complete
 
 Plans:
 - [x] 21-00-PLAN.md — Wave 0 test stubs (chat-service, chat-routes, ChatMarkdownMessage, ChatInput)
@@ -40,7 +40,7 @@ Plans:
 - [x] 21-03-PLAN.md — Server chat service and REST API routes (CRUD + pagination)
 - [x] 21-04-PLAN.md — ChatPanel shell, ChatPanelContext, ChatInput, Layout integration
 - [x] 21-05-PLAN.md — Full UI wiring: API client, conversation list, message thread, infinite scroll
-- [ ] 21-06-PLAN.md — Gap closure: conversation search/filter (HIST-02) + Cmd+K shortcut (INPUT-07)
+- [x] 21-06-PLAN.md — Gap closure: conversation search/filter (HIST-02) + Cmd+K shortcut (INPUT-07)
 
 **UI hint**: yes
 
@@ -190,7 +190,7 @@ All 65 v1 requirements are mapped to exactly one phase. No orphans.
 
 | Phase | Milestone | Plans Complete | Status | Completed |
 |-------|-----------|----------------|--------|-----------|
-| 21. Chat Foundation | v1.3 | 6/7 | Gap closure | - |
+| 21. Chat Foundation | v1.3 | 7/7 | Complete   | 2026-04-01 |
 | 22. Agent Streaming | v1.3 | 0/? | Not started | - |
 | 23. Brainstormer Flow | v1.3 | 0/? | Not started | - |
 | 24. Search, History & Branching | v1.3 | 0/? | Not started | - |

.planning/STATE.md

@@ -2,15 +2,15 @@
 gsd_state_version: 1.0
 milestone: v1.3
 milestone_name: milestone
-status: executing
+status: verifying
-stopped_at: Completed 21-chat-foundation-21-05-PLAN.md
+stopped_at: Completed 21-chat-foundation-21-06-PLAN.md
-last_updated: "2026-04-01T17:00:47.388Z"
+last_updated: "2026-04-01T17:16:25.961Z"
 last_activity: 2026-04-01
 progress:
   total_phases: 6
   completed_phases: 1
-  total_plans: 6
+  total_plans: 7
-  completed_plans: 6
+  completed_plans: 7
   percent: 0
 ---
 
@@ -27,7 +27,7 @@ See: .planning/PROJECT.md (updated 2026-03-30)
 
 Phase: 21 (chat-foundation) — EXECUTING
 Plan: 6 of 6
-Status: Ready to execute
+Status: Phase complete — ready for verification
 Last activity: 2026-04-01
 
 Progress: [░░░░░░░░░░] 0%
@@ -65,6 +65,7 @@ Progress: [░░░░░░░░░░] 0%
 | Phase 21-chat-foundation P04 | 4min | 2 tasks | 7 files |
 | Phase 21-chat-foundation P03 | 6 | 2 tasks | 6 files |
 | Phase 21-chat-foundation P05 | 4 | 3 tasks | 8 files |
+| Phase 21-chat-foundation P06 | 10min | 2 tasks | 7 files |
 
 ## Accumulated Context
 
@@ -94,6 +95,8 @@ Recent decisions affecting current work:
 - [Phase 21-03]: Missing export fix: createConversationSchema/updateConversationSchema/createMessageSchema were in validators/chat.ts but not re-exported from shared/src/index.ts
 - [Phase 21-chat-foundation]: Two-path handleSend in ChatPanel: direct chatApi for path 1 (no active conversation) avoids hook mutation needing a conversationId that does not exist yet
 - [Phase 21-chat-foundation]: messages array in useChatMessages flattened from pages and reversed so display is chronological (API returns desc by createdAt)
+- [Phase 21-chat-foundation]: Custom window event (nexus:focus-chat-search) used instead of forwardRef drilling to focus search input from Cmd+K
+- [Phase 21-chat-foundation]: Cmd+K handler placed before input-guard early return in useKeyboardShortcuts so it fires globally even from input/textarea
 
 ### Pending Todos
 
@@ -106,6 +109,6 @@ None yet.
 
 ## Session Continuity
 
-Last session: 2026-04-01T17:00:47.384Z
+Last session: 2026-04-01T17:16:25.958Z
-Stopped at: Completed 21-chat-foundation-21-05-PLAN.md
+Stopped at: Completed 21-chat-foundation-21-06-PLAN.md
 Resume file: None

.planning/phases/21-chat-foundation/21-06-SUMMARY.md

@@ -0,0 +1,68 @@
+---
+phase: 21-chat-foundation
+plan: "06"
+subsystem: chat
+tags: [chat, search, keyboard-shortcuts, filtering]
+dependency_graph:
+  requires: []
+  provides: [HIST-02, INPUT-07]
+  affects: [ChatConversationList, useChatConversations, chatApi, chatService, chatRoutes, useKeyboardShortcuts, Layout]
+tech_stack:
+  added: []
+  patterns: [custom-event-bus, debounced-input, ilike-filter, global-keyboard-shortcut]
+key_files:
+  created: []
+  modified:
+    - server/src/services/chat.ts
+    - server/src/routes/chat.ts
+    - ui/src/api/chat.ts
+    - ui/src/hooks/useChatConversations.ts
+    - ui/src/components/ChatConversationList.tsx
+    - ui/src/hooks/useKeyboardShortcuts.ts
+    - ui/src/components/Layout.tsx
+decisions:
+  - "Used custom window event (nexus:focus-chat-search) instead of forwardRef drilling to focus search input from Cmd+K — avoids threading refs through ChatPanel"
+  - "Debounce search at 300ms via useEffect+setTimeout pattern to avoid flooding the server with requests on every keystroke"
+  - "Cmd+K handler placed before the input-guard early return in useKeyboardShortcuts so it fires even when typing in inputs/textareas"
+metrics:
+  duration: "~10 min"
+  completed: "2026-04-01"
+  tasks: 2
+  files: 7
+---
+
+# Phase 21 Plan 06: Chat Search and Cmd+K Shortcut Summary
+
+Gap closure for HIST-02 (conversation search) and INPUT-07 (Cmd+K keyboard shortcut): server-side ilike filtering on conversation titles with a debounced search input, plus Cmd+K to open chat panel and focus search.
+
+## What Was Built
+
+### Task 1: Server-side search and agentId filtering
+- `chatService.listConversations` extended with `search?: string` and `agentId?: string` opts; adds `ilike(chatConversations.title, '%term%')` and `eq(chatConversations.agentId, id)` conditions when provided
+- `GET /companies/:companyId/conversations` route extracts `search` and `agentId` from `req.query`
+- `chatApi.listConversations` serializes `search` and `agentId` as URL query params
+- `useChatConversations` accepts `opts?: { search?: string }`, includes search in queryKey (triggers refetch on change), passes to API
+
+### Task 2: Search input UI and Cmd+K shortcut
+- `ChatConversationList` renders a search input with Search icon (left) and clear X button (right); 300ms debounce; passes debouncedSearch to `useChatConversations`
+- `ChatConversationList` listens for `nexus:focus-chat-search` custom window event to focus the input
+- `useKeyboardShortcuts` adds `onSearch?: () => void` to `ShortcutHandlers`; Cmd+K/Ctrl+K handler is placed BEFORE the input-guard early return (fires globally)
+- `Layout` wires `onSearch` to open chat panel if closed, then dispatches `nexus:focus-chat-search` via `requestAnimationFrame`
+
+## Verification Results
+
+- TypeScript: no new chat-related errors in server or UI (pre-existing plugin-sdk errors in plugins.ts are out of scope)
+- All tests pass: chat-service (21), chat-routes (11), ChatMarkdownMessage (4), ChatInput (6) — 42 total
+- Search input present with placeholder "Search conversations..."
+- Cmd+K handler on `metaKey || ctrlKey` + `k` in useKeyboardShortcuts
+- Route passes search/agentId params
+
+## Deviations from Plan
+
+None — plan executed exactly as written. Used the simpler custom-event approach (suggested as ALTERNATIVE in plan) rather than forwardRef/useImperativeHandle, as plan explicitly recommended this path.
+
+## Known Stubs
+
+None.
+
+## Self-Check: PASSED