feat: Discord links, translation sync, iOS login fix, trip copy fix

- Add Discord button to admin GitHub panel and user menu
- Sync all 13 translation files to 1434 keys with native translations
- Fix duplicate keys in Polish translation (pl.ts)
- Fix iOS login race condition: sameSite strict→lax, loadUser sequence counter
- Fix trip copy route: add missing db, Trip, TRIP_SELECT imports

server/src/services/cookie.ts

@@ -7,7 +7,7 @@ export function cookieOptions(clear = false) {
   return {
     httpOnly: true,
     secure,
-    sameSite: 'strict' as const,
+    sameSite: 'lax' as const,
     path: '/',
     ...(clear ? {} : { maxAge: 24 * 60 * 60 * 1000 }), // 24h — matches JWT expiry
   };