AppForge: migrate off Supabase to external Postgres + Better Auth + local storage

- New Express + TypeScript backend (server/) with pg, Better Auth, local file storage
- De-Supabased Postgres schema (server/db) and TS reimplementations of DB functions
- Frontend data layer rewired to REST (rest-client + backend-client compat shim)
- Removed all Supabase references (code, config, deps, docs)
- New brand assets: gradient favicon/app icons + dark/white wordmark logos

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

tsconfig.json

@@ -0,0 +1,24 @@
+{
+  "compilerOptions": {
+    "allowJs": true,
+    "noImplicitAny": false,
+    "noUnusedLocals": false,
+    "noUnusedParameters": false,
+    "paths": {
+      "@/*": [
+        "./src/*"
+      ]
+    },
+    "skipLibCheck": true,
+    "strictNullChecks": false
+  },
+  "files": [],
+  "references": [
+    {
+      "path": "./tsconfig.app.json"
+    },
+    {
+      "path": "./tsconfig.node.json"
+    }
+  ]
+}