feat: TLS/SSL wrapper, architecture docs — 251 tests
TLS/SSL ():
- TLS socket wrapper with connect/accept/send/recv
- Certificate management (info parsing, fingerprint, expiry check)
- Self-signed certificate generation via openssl
- Certificate validation with error reporting
Architecture Documentation ():
- Complete 5-layer architecture overview
- Data flow walkthrough (write path, read path, vector search, graph)
- Key design decisions and trade-offs
- Module count and estimated line counts per category
- All 48 modules documented with descriptions
5 new tests (251 total, all passing)