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/design.md

@@ -1,46 +0,0 @@
-## Context
-
-Yjs awareness already tracks users with `{ color, name }` state and renders
-map cursors via `CursorTracker` in `PlannerMap.tsx`. The current implementation
-has issues: random names can't be changed, cursor labels are unstyled, and
-there's no participant list showing who's in the session.
-
-## Goals / Non-Goals
-
-**Goals:**
-- See all participants in the session (name, color, host/participant role)
-- Edit your own name (saved to localStorage, synced via awareness)
-- Polished cursor rendering on the map
-- Visual feedback when someone joins or leaves
-
-**Non-Goals:**
-- Chat or messaging between participants
-- Cursor position sharing outside the map (e.g., in the sidebar)
-- Participant permissions or kicking (admin-only debug feature already exists)
-
-## Decisions
-
-### D1: Participant list in session header
-
-Show colored dots + names in the header bar (already has space between profile
-selector and connection status). Clicking your own name opens an inline edit.
-Keeps the sidebar free for waypoints.
-
-### D2: Name persisted in localStorage, synced via awareness
-
-Current approach: random name from a list, stored in localStorage as
-`trails:user`. Enhancement: let users edit it. On change, update localStorage
-AND call `awareness.setLocalStateField("user", { color, name })`. All other
-clients see the update immediately.
-
-### D3: Cursor as SVG pointer with name tag
-
-Replace the current `divIcon` cursor label with: a small SVG arrow in the
-user's color + a name tag with background, shadow, and rounded corners.
-Position offset so the pointer tip is at the actual lat/lng.
-
-### D4: Join/leave toasts
-
-When awareness detects a new client or a client leaving, show a brief toast
-("Alice joined" / "Bob left") that auto-dismisses after 3 seconds. Use a
-simple absolute-positioned div, no toast library.