feat: Add comprehensive lexicon test data and validation fixes

- Add 35 test data files covering all lexicon record types
- Actor records: block, membership, preferences, profile, saved, subscription
- Community records: moderator, profile, rules, wiki
- Interaction records: comment, share, tag
- Moderation records: ruleProposal, tribunalVote, vote
- Post records: post validation

- Fix lexicon schema issues:
- Add 'handle' format to actor profile
- Fix typo in community profile moderation type
- Add required $type field to interaction comments
- Add minItems constraint to tag arrays
- Fix enum values in moderation schemas

- Improve validate-lexicon tool:
- Better number handling to prevent float64 conversion issues
- Add json.Number support for accurate integer validation

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

feat: Implement comprehensive lexicon validation system