feat(lexicon): add reusable defs and remove unimplemented features
- Add social.coves.actor.defs.json with profileView, profileViewDetailed,
profileStats, viewerState, and geoLocation definitions
- Add social.coves.community.defs.json with communityView, communityViewDetailed,
communityStats, and viewerState definitions
- Remove unimplemented actor lexicons: block, blockUser, unblockUser, saved,
saveItem, unsaveItem, getSaved, preferences
- Remove duplicate actor.subscription (replaced by community.subscription)
Following atProto best practices: reusable definitions in defs.json,
removing unimplemented features from pre-production codebase.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>