- Use vec_f32() to convert JSON query vectors to binary format
- Clean up test data in setup to ensure test isolation
- Fix dimension mismatch by ensuring tests use isolated data
- All 123 tests now passing

The issue was that find_similar was trying to compare vectors of
different dimensions (test vectors were 3-dim, production vectors
were 1536-dim from real embeddings). Adding cleanup in test setup
ensures tests are properly isolated from production data.

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

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