Add configurable GIF and local media picker

[astroboii47]

Summary

• add an optional Klipy-powered GIF/sticker/meme picker as a SYM page
• add local media folder support so users can pick/send their own local images
• add GIF/media API-key configuration under Smart Features
• support sending media through commitContent with fallback link/copy behavior when apps do not accept keyboard media

Notes

• no API key is bundled by default; the Gradle property defaults to blank and users can enter their own key in settings
• the picker can be enabled or disabled from SYM keyboard customization

Testing

• ./gradlew :app:assembleDebug

[astroboii47]

Closing in favor of #259, which contains the cleaned combined feature set with split commits.