Add deploy startup seed guard

prisma/seed-if-empty.ts

@@ -0,0 +1,42 @@
+import { PrismaClient } from "@prisma/client";
+import { spawn } from "node:child_process";
+
+const prisma = new PrismaClient();
+
+async function runSeed() {
+  await new Promise<void>((resolve, reject) => {
+    const child = spawn("npx", ["tsx", "prisma/seed.ts"], {
+      stdio: "inherit",
+      shell: true
+    });
+    child.on("exit", (code) => {
+      if (code === 0) resolve();
+      else reject(new Error(`Seed failed with exit code ${code}`));
+    });
+  });
+}
+
+async function main() {
+  const [plans, users, ads] = await Promise.all([
+    prisma.plan.count(),
+    prisma.user.count(),
+    prisma.ad.count()
+  ]);
+
+  if (plans > 0 && users > 0 && ads > 0) {
+    console.log("✅ Database already seeded. Skipping demo seed.");
+    return;
+  }
+
+  console.log("🌱 Empty database detected. Running demo seed...");
+  await runSeed();
+}
+
+main()
+  .catch((error) => {
+    console.error(error);
+    process.exit(1);
+  })
+  .finally(async () => {
+    await prisma.$disconnect();
+  });