feat: bootstrap SuperAdmin from env and lock one-time seeding

Production creates the SuperAdmin from env credentials, and dashboard seeding is authenticated, SuperAdmin-only, and locked after the first run.

components/seed/seedController.js

@@ -0,0 +1,16 @@
+// /components/seed/seedController.js
+'use strict';
+
+const catchAsync = require('../../utils/catchAsync');
+const seedService = require('./seedService');
+const { successResponse } = require('../../utils/apiResponse');
+
+exports.getStatus = catchAsync(async (req, res) => {
+  const status = await seedService.getStatus();
+  return successResponse(res, 200, 'Seed status retrieved', status);
+});
+
+exports.runSeed = catchAsync(async (req, res) => {
+  const result = await seedService.runSeed(req.user?._id);
+  return successResponse(res, 200, 'Database seeded successfully', result);
+});