4:3 Library v0.1.4

Fix the real Steam Deck runtime and native library tab injection.\n\n- Import sibling backend modules correctly under Decky\n- Use SteamOS CA bundles for curator refreshes\n- Inject the native 4:3 tab through the current Steam library renderer\n- Avoid route navigation that dismisses Quick Access\n- Harden deployment for root-owned Decky plugin directories