WebAuthn biometric + PWA widget + UI header fixes + mobile responsive

- WebAuthn: register/auth options, device management
- PWA widget page + manifest shortcuts
- Group schedule endpoint (timezones + locations)
- UI #3-#6: compact headers on tasks/calendar/projects/goals
- UI #9: mobile responsive top bars
- webauthn_credentials table

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

apps/tasks/package.json

@@ -13,6 +13,7 @@
     "@fullcalendar/interaction": "^6.1.20",
     "@fullcalendar/react": "^6.1.20",
     "@fullcalendar/timegrid": "^6.1.20",
+    "@simplewebauthn/browser": "^12.0.0",
     "next": "14.2.35",
     "react": "^18",
     "react-dom": "^18",