Add Sentry error tracking to both apps

Planner (client + custom server) and Journal (client + entry.server):
- Client: @sentry/react with browser tracing + replay on error
- Server: @sentry/node for unhandled exceptions
- ErrorBoundary captures React errors via Sentry.captureException
- Disabled in dev, 10% trace sample rate in production

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

apps/journal/package.json

@@ -13,6 +13,8 @@
   "dependencies": {
     "@react-router/node": "catalog:",
     "@react-router/serve": "catalog:",
+    "@sentry/node": "^10.45.0",
+    "@sentry/react": "^10.45.0",
     "@simplewebauthn/browser": "^13.3.0",
     "@simplewebauthn/server": "^13.3.0",
     "@trails-cool/db": "workspace:*",