feat: polish toolbar, live online count via SSE + emulator 3-state

- Add emulator status 3-state (unknown/green/red) with tooltip
- Extract shared primary button style/constants for DRY toolbar code
- Add emulatorUnknown translations to all 25 locales
- Bump Next.js to 16.3.4
- Fix RCON delivery timeout caching (15s TTL / shared across clients)
- Who's-online tooltip throttled to max 1 request per 30s

package.json

@@ -54,7 +54,7 @@
 		"motion": "13.1.1",
 		"music-metadata": "11.15.0",
 		"mysql2": "3.24.2",
-		"next": "16.3.3",
+		"next": "16.3.4",
 		"next-auth": "5.0.0-beta.32",
 		"next-intl": "4.14.1",
 		"otplib": "13.5.0",