Replace fontsource with next/font/google and update react-zen.

- Switch from @fontsource/inter to next/font/google for font loading
- Update @umami/react-zen to v0.229.0
- Add type augmentation for react-zen missing children props
- Move global.css to app directory

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

package.json

@@ -65,7 +65,6 @@
     "@date-fns/utc": "^1.2.0",
     "@dicebear/collection": "^9.2.3",
     "@dicebear/core": "^9.2.3",
-    "@fontsource/inter": "^5.2.8",
     "@hello-pangea/dnd": "^17.0.0",
     "@prisma/adapter-pg": "^7.2.0",
     "@prisma/client": "^7.2.0",
@@ -73,7 +72,7 @@
     "@react-spring/web": "^10.0.3",
     "@svgr/cli": "^8.1.0",
     "@tanstack/react-query": "^5.90.17",
-    "@umami/react-zen": "^0.216.0",
+    "@umami/react-zen": "^0.229.0",
     "@umami/redis-client": "^0.30.0",
     "bcryptjs": "^3.0.2",
     "chalk": "^5.6.2",