feat: add guest access code management

[alex4108]

Summary

• add typed guest-access policy and credential models
• list unit access data without exposing resident credentials through guest-only helpers
• create, update, and delete permanent, temporary, and recurring guest codes
• enforce SmartRent policy limits before sending mutations
• accept a caller-provided SSL context for WebSocket connections
• omit the ssl argument when no context is supplied, fixing current websockets behavior for wss:// connections

API contract

The guest-code endpoints and payloads were cross-checked against SmartRent's current Resident clients. Create uses the unit guest-access endpoint; update and delete use the credential endpoint returned by the unit access response.

Safety

• validation rejects malformed schedules and unsupported policy combinations before a write
• guest helpers operate only on guests[].pin_codes
• diagnostics and exceptions avoid logging plaintext PINs or access payloads
• resident, mobile, and fob credentials are not accepted by guest mutation helpers

Verification

• 29 tests pass
• coverage includes policy validation, temporary and recurring payloads, response parsing, credential mutation paths, redaction, SSL context injection, and the secure-WebSocket ssl=None regression