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/route-features/proposal.md

@@ -0,0 +1,43 @@
+## Why
+
+Routes are currently flat — no permissions beyond owner, no way to share with
+specific people, no forking, no multi-day support, no spatial discovery, and
+no contributor tracking. The architecture doc specifies all of these for Phase
+2. Without them, routes are just personal GPX storage with no social or
+collaborative dimension.
+
+## What Changes
+
+- **Route sharing permissions**: Private/public/shared visibility levels with
+  a view/edit permission matrix
+- **Route forking**: Copy someone else's public route to your own collection
+- **Multi-day routes**: Day-break waypoints that split a route into stages with
+  per-day stats and GPX segments
+- **Spatial search**: "Routes near me" or "routes in this area" using PostGIS
+- **Contributor tracking**: Record who contributed to each route version
+- **Activity visibility levels**: Public/followers-only/private on activities
+- **Photo attachments**: Upload photos to activities (requires S3/Garage setup)
+
+## Capabilities
+
+### New Capabilities
+
+- `route-sharing`: Permission model (private/public/shared), view/edit access, route forking
+- `spatial-search`: Map-based route discovery using PostGIS bounding box and proximity queries
+- `multi-day-routes`: Day-break markers on waypoints, per-day stats, multi-segment GPX export
+- `activity-photos`: Photo upload and display on activities via S3-compatible storage
+
+### Modified Capabilities
+
+- `route-management`: Add visibility, contributor tracking, forking
+- `activity-feed`: Add visibility levels (public/followers-only/private)
+- `planner-session`: Support day-break waypoint markers
+- `infrastructure`: S3/Garage setup for photo storage
+
+## Impact
+
+- **Database**: New columns (visibility, contributors) on routes and activities, new route_shares table, photo storage metadata
+- **Storage**: S3-compatible object storage (Garage) for photos
+- **Files**: Route detail page, activity pages, search page, Planner waypoint UI, sharing UI
+- **Dependencies**: S3 client library for photo uploads
+- **Privacy**: Photo storage, route visibility controls documented in manifest