Archive app-navigation and planner-multiplayer-awareness, sync specs

Both changes fully implemented. Sync delta specs to main:
- map-display: add Planner home page nav and cursor rendering requirements
- planner-session: add session participant awareness requirement

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

openspec/changes/planner-multiplayer-awareness/tasks.md

@@ -1,27 +0,0 @@
-## 1. Name Editing
-
-- [x] 1.1 Update use-yjs.ts: allow updating user name via a returned setter function
-- [x] 1.2 Save updated name to localStorage and sync via awareness.setLocalStateField
-- [x] 1.3 Add i18n keys for participant UI (en + de)
-
-## 2. Participant List
-
-- [x] 2.1 Create ParticipantList component showing all awareness states (name, color dot, host badge)
-- [x] 2.2 Add inline name edit when clicking own name in the list
-- [x] 2.3 Integrate ParticipantList into SessionView header
-
-## 3. Cursor Styling
-
-- [x] 3.1 Replace current divIcon cursor with SVG pointer arrow + styled name tag (background, shadow, rounded)
-- [x] 3.2 Set cursor z-index below map controls to avoid overlap
-
-## 4. Join/Leave Toasts
-
-- [x] 4.1 Track awareness changes (added/removed clients) in SessionView
-- [x] 4.2 Show auto-dismissing toast when participant joins or leaves (3 second duration)
-
-## 5. Verify
-
-- [x] 5.1 Test with two browser windows: verify participant list, name editing, cursor rendering
-- [x] 5.2 Verify join/leave toasts appear correctly
-- [x] 5.3 Verify name persists across page refresh (localStorage)