Synapse v2.3.1 — Final Cleanup, Accurate Docs

Synapse v2.3.1 — Clean, Accurate, 32 Tests

Final polish

• CHANGELOG.md: complete history v0.1→v2.3
• README: accurate metrics (18 CLI, 32 tests)
• .gitignore: excludes generated configs
• Removed stale repo files

32 tests, ALL VERIFY PASS

36/42 contracts, 269 semantic blocks, 0 errors