v1.27

Keyless place search release.\n\n- Replaced LLM and Google Places sources with OpenStreetMap search.\n- Added Overpass search with Photon fallback for nearby places.\n- Removed API-key setup from the app UI.\n- Updated README and app version to 1.27.\n\nValidation: .\gradlew.bat --no-daemon testDebugUnitTest assembleDebug