Add 8 proposed changes and old trails analysis

Proposed changes (all with proposal, design, specs, tasks):
- app-navigation (9 tasks) — nav bars for both apps
- planner-landing-page (7 tasks) — standalone landing page
- planner-multiplayer-awareness (13 tasks) — participants, cursors, names
- changelog (13 tasks) — public changelog with "what's new"
- transactional-emails (15 tasks) — magic link + welcome emails
- planner-features (18 tasks) — no-go areas, notes, recovery, rate limits
- komoot-import (23 tasks) — Komoot tour import
- route-features (37 tasks) — sharing, multi-day, spatial, photos

Also adds docs/old-trails-analysis.md with feature analysis from the
older trails project.

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

openspec/changes/planner-features/design.md

@@ -0,0 +1,74 @@
+## Context
+
+The Planner architecture defines noGoAreas, notes, and crash recovery in the
+Yjs data model but none are implemented. The public instance also lacks rate
+limiting — anyone can create unlimited sessions or hammer BRouter.
+
+## Goals / Non-Goals
+
+**Goals:**
+- Draw no-go polygons on the map, synced via Yjs, sent to BRouter
+- Shared notes (Y.Text) visible in sidebar for planning discussion
+- localStorage backup of Yjs state, merged on reconnect
+- Rate limits: 10 sessions/IP/hour, 60 BRouter calls/session/hour
+
+**Non-Goals:**
+- Complex polygon editing (holes, multi-polygon) — just simple polygons
+- Rich text in notes (just plain text)
+- Cross-tab Yjs sync via localStorage (handled by WebSocket)
+- Rate limiting dashboard or admin UI
+
+## Decisions
+
+### D1: No-go areas as Yjs Y.Array of polygon coordinates
+
+```typescript
+// Yjs doc structure addition
+noGoAreas: Y.Array<Y.Map<{
+  points: Array<{lat: number, lon: number}>,
+  name?: string
+}>>
+```
+
+Each polygon is a closed ring of lat/lon points. BRouter accepts no-go areas
+as a `nogo` parameter: `lon,lat,radius` for circles or polygon coordinates
+depending on the BRouter version. We'll convert our polygons to BRouter's
+expected format in the routing request.
+
+### D2: Leaflet.draw for polygon drawing
+
+Use `leaflet-draw` (or `@geoman-io/leaflet-geoman-free`) for drawing polygons
+on the map. When a polygon is completed, add it to the Y.Array. Existing
+polygons render as semi-transparent red overlays.
+
+### D3: Notes as Y.Text in sidebar tab
+
+Add a "Notes" tab to the sidebar (alongside waypoints). Uses Y.Text for
+collaborative editing — simple textarea bound to Y.Text. Changes sync in
+real-time. No markdown rendering — plain text only.
+
+### D4: localStorage crash recovery
+
+Every 10 seconds, save `Y.encodeStateAsUpdate(doc)` to
+`localStorage['trails:session:${id}']`. On page load, if localStorage has
+state for the current session, apply it as an update before connecting to
+the server. Yjs CRDTs merge automatically — no conflicts.
+
+Clear localStorage entry when session is closed or after successful sync.
+
+### D5: In-memory rate limiter
+
+Simple Map-based rate limiter in `server.ts`:
+- Session creation: Track IP → count + window. Reject with 429 after 10/hour.
+- BRouter proxy: Track session ID → count + window. Reject after 60/hour.
+- No Redis needed — single server, in-memory is fine. Resets on restart
+  (acceptable).
+
+## Risks / Trade-offs
+
+- **leaflet-draw adds bundle size** → ~50KB gzipped. Acceptable for polygon
+  drawing functionality. Can lazy-load.
+- **localStorage size limit** → ~5MB per origin. Yjs state is typically
+  10-100KB. No risk.
+- **In-memory rate limiter resets on deploy** → Acceptable for current scale.
+  Redis-backed when needed.