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/app-navigation/tasks.md

@@ -0,0 +1,18 @@
+## 1. Journal Navigation Bar
+
+- [ ] 1.1 Add nav bar to Journal root Layout — show "Routes", "Activities" links when logged in; "Login", "Register" when logged out
+- [ ] 1.2 Add user menu to nav bar — username/display name linking to profile, logout button
+- [ ] 1.3 Highlight active nav item based on current route
+- [ ] 1.4 Add i18n keys for nav labels (en + de): routes, activities, profile, logout
+
+## 2. Planner Navigation
+
+- [ ] 2.1 Add "Start Planning" CTA button on Planner home page linking to `/new`
+- [ ] 2.2 Add home link (logo or text) to SessionView header
+- [ ] 2.3 Add i18n keys for planner nav (en + de): startPlanning, home
+
+## 3. Verify
+
+- [ ] 3.1 Verify all Journal routes are reachable via navigation (routes, activities, profile, auth, privacy)
+- [ ] 3.2 Verify Planner home → new session → back to home works
+- [ ] 3.3 Update E2E tests if navigation changes affect existing selectors