- proxy.ts: /ideas added to protectedRoutes — unauthenticated users get
redirected to /login when navigating to /ideas or /ideas/[id]
- existing demo-guard catch-all (\`/api/* + non-GET\`) already blocks
POST/PATCH/DELETE /api/ideas* with 403 — confirmed via 3 new tests
- server-action endpoints (start-grill / start-make-plan / materialize /
promote-to-idea) carry their own \`session.isDemo\` checks inside
actions/ideas.ts and actions/todos.ts (defense in depth)
Tests: 9/9 in proxy demo-guard suite (added 3 idea cases).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>