Lemenzo Gallery v1.14 - System Integration Candidate

- Added Android ACTION_VIEW handlers for image/* and video/*.
- Viewer accepts incoming content URIs and safely falls back to single-item mode for non-MediaStore content.
- MediaStore-only Favorite/Trash actions are hidden in external single-item mode.
- Removed unnecessary privileged-app installation flag.
- Added revocable default media permission grant configuration for the preinstalled system Gallery.
- Added product integration makefile snippet that replaces AOSP Gallery2 with LemenzoGallery.
- Added documented standard Lemenzo Camera -> Gallery ACTION_VIEW contract.
- Preserved no-INTERNET and no-MANAGE_EXTERNAL_STORAGE privacy invariants.