MediaResourceProvider
Serves photos and videos as MCP resources: resources/list advertises the RECENT_LIMIT most recent images and videos, and resources/read on a content://media/external/{images,video}/media/<id> URI returns the file as a base64 blob. Items over MAX_BYTES can't be read (use get_media_metadata for those). Needs the same permissions as MediaTools; without them the listing is empty and reads fail as not found. Hidden while get_media_metadata is gated off.