fix: fix db restore not applying and auto-create USB backup folder

- Reset public schema before psql restore so existing tables don't
  block CREATE TABLE statements (pg_dump without --clean has no DROPs)
- Disconnect Prisma connection pool after restore so next request
  gets fresh connections against the restored data
- Auto-create the USB backup subfolder if it doesn't exist instead
  of failing; only fail if the destination drive itself is missing

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/Backend/src/routes/database-management.ts

@@ -339,6 +339,17 @@ router.post("/restore", restoreUpload.single("file"), async (req: Request, res:
 
   if (!req.file) return res.status(400).json({ error: "No file provided" });
 
+  // Drop and recreate the public schema so existing tables don't block the restore.
+  // pg_dump without --clean produces no DROP statements, so restoring into an
+  // existing schema would silently skip CREATE TABLE / fail on duplicate inserts.
+  try {
+    await prisma.$executeRawUnsafe(`DROP SCHEMA public CASCADE`);
+    await prisma.$executeRawUnsafe(`CREATE SCHEMA public`);
+  } catch (err: any) {
+    console.error("Failed to reset schema before restore:", err);
+    return res.status(500).json({ error: "Failed to reset database schema", details: err.message });
+  }
+
   const psql = spawn(
     "psql",
     [
@@ -360,11 +371,20 @@ router.post("/restore", restoreUpload.single("file"), async (req: Request, res:
       res.status(500).json({ error: "Failed to run psql", details: err.message });
   });
 
-  psql.on("close", (code) => {
+  psql.on("close", async (code) => {
     if (code !== 0) {
       console.error("psql restore failed:", stderr);
       return res.status(500).json({ error: "Restore failed", details: stderr });
     }
+
+    // Disconnect so Prisma drops its pooled connections and reconnects fresh
+    // on the next request, avoiding stale prepared statements against the old schema.
+    try {
+      await prisma.$disconnect();
+    } catch (_) {
+      // non-fatal — the restore succeeded
+    }
+
     res.json({ success: true });
   });