feat: auto-migration on startup (ensureSchema)

- db.js: ensureSchema() creates tables if not exist
- server.js: calls ensureSchema() after DB connection
- No manual SQL needed for deployment

server.js

@@ -23,7 +23,7 @@ const path = require('path');
 const helmet = require('helmet');
 require('dotenv').config();
 
-const { checkConnection }  = require('./src/db');
+const { checkConnection, ensureSchema }  = require('./src/db');
 const { initAuth }         = require('./src/auth');
 const q                    = require('./src/queries');
 const { MOCK_USERS, APP_VERSION } = require('./src/config');
@@ -127,7 +127,7 @@ async function start() {
 
   // ── Старт сервера ─────────────────────────────────────────────────────────────
   checkConnection()
-    .then(() => console.log('DB connected'))
+    .then(() => { console.log('DB connected'); return ensureSchema(); })
     .catch(e => console.error('DB not ready:', e.message));
 
   return app;