Implement Planner-Journal handoff (Group 9)

JWT-based handoff between Journal and Planner:

Journal side:
- JWT token generation scoped to route_id with 7-day expiry (jose)
- "Edit in Planner" button on route detail page — generates JWT,
  redirects to Planner /new with callback URL, token, and GPX
- Callback endpoint (POST /api/routes/:id/callback) validates JWT
  and creates new route version from received GPX

Planner side:
- /new route accepts callback, token, returnUrl, gpx params
- Creates session with callback metadata, initializes with GPX
- "Save to Journal" button POSTs GPX with Bearer token to callback
- "Return to Journal" link shown after successful save

All 6 Group 9 tasks complete.

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

apps/journal/package.json

@@ -23,6 +23,7 @@
     "@trails-cool/ui": "workspace:*",
     "drizzle-orm": "catalog:",
     "isbot": "^5.1.0",
+    "jose": "^6.2.2",
     "react": "catalog:",
     "react-dom": "catalog:",
     "react-router": "catalog:"