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>

server/src/routes/storage.ts

@@ -0,0 +1,38 @@
+import { Router } from 'express';
+import multer from 'multer';
+import { h } from '../lib/respond.js';
+import { requireAuth, type AuthedRequest } from '../middleware/auth.js';
+import { writeFile, deleteFile, listFiles, publicUrl } from '../lib/storage.js';
+
+const r = Router();
+const upload = multer({ storage: multer.memoryStorage(), limits: { fileSize: 600 * 1024 * 1024 } });
+
+// POST /storage/upload  (multipart: bucket, path, file)
+r.post('/upload', requireAuth, upload.single('file'), h(async (req: AuthedRequest) => {
+  const bucket = req.body.bucket as string;
+  const relPath = (req.body.path as string) || (req as any).file?.originalname;
+  const file = (req as any).file;
+  if (!file) throw new Error('No file provided');
+  if (!bucket) throw new Error('No bucket provided');
+  const result = writeFile(bucket, relPath, file.buffer);
+  return result;
+}));
+
+// DELETE /storage  (body: bucket, path)
+r.delete('/', requireAuth, h(async (req) => {
+  const { bucket, path: relPath } = req.body || {};
+  deleteFile(bucket, relPath);
+  return { message: 'File deleted successfully' };
+}));
+
+// GET /storage/list?bucket=&folder=
+r.get('/list', requireAuth, h(async (req) => {
+  return listFiles(req.query.bucket as string, (req.query.folder as string) || '');
+}));
+
+// GET /storage/public-url?bucket=&path=
+r.get('/public-url', h(async (req) => {
+  return { url: publicUrl(req.query.bucket as string, req.query.path as string) };
+}));
+
+export default r;