refactor: explicit migrate/seed scripts, no auto-init at server start

Auto-running migrations on every server boot is dangerous — a broken
migration silently corrupts data or blocks server start. Now require
explicit `npm run migrate && npm run seed:permissions` before start.
Boot asserts schema exists (users + role_permissions tables) and
fails fast with a clear message otherwise.

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

backend/package.json

@@ -8,6 +8,7 @@
     "dev": "nodemon src/server.js",
     "migrate": "node src/db/migrate.js",
     "seed": "node src/db/seed.js",
+    "seed:permissions": "node src/db/seed-permissions.js",
     "test": "node --test tests/*.test.js"
   },
   "dependencies": {

backend/src/db/seed-permissions.js

@@ -0,0 +1,4 @@
+'use strict';
+require('../controllers/permissionsController').seedDefaults();
+require('../controllers/gamificationController').seedAchievements();
+console.log('[seed-permissions] OK');

backend/src/server.js

@@ -1,9 +1,19 @@
 const config = require('./config');        // validates .env, fails fast on error
 const logger = require('./utils/logger');  // structured logging
 
-require('./db/migrate'); // авто-миграция при каждом старте
-const { seedDefaults: seedPermissions } = require('./controllers/permissionsController');
-seedPermissions();
+/* ── Schema check — fail fast if migrate hasn't been run ── */
+const _bootDb = require('./db/db');
+try {
+  _bootDb.prepare('SELECT 1 FROM users LIMIT 1').get();
+  _bootDb.prepare('SELECT 1 FROM role_permissions LIMIT 1').get();
+} catch (e) {
+  process.stderr.write(
+    '[boot] FATAL: schema not initialized.\n' +
+    'Run: npm run migrate && npm run seed:permissions\n'
+  );
+  process.exit(1);
+}
+
 const express     = require('express');
 const cors        = require('cors');
 const path        = require('path');