Add persistent chat session state (ChatState, sequence tracking, tool
calls). Introduce basic billing record in agent crate. Refine chat
service to route messages through state machine with tool support.
Model sync:
- Filter OpenRouter models by what the user's AI client can actually access,
before upserting metadata (avoids bloating with inaccessible models).
- Fall back to direct endpoint sync when no OpenRouter metadata matches
(handles Bailian/MiniMax and other non-OpenRouter providers).
Git stability fixes:
- SSH: add 5s timeout on stdin flush/shutdown in channel_eof and
cleanup_channel to prevent blocking the event loop on unresponsive git.
- SSH: remove dbg!() calls from production code paths.
- HTTP auth: pass proper Logger to SshAuthService instead of discarding
all auth events to slog::Discard.
Dependencies:
- reqwest: add native-tls feature for HTTPS on Windows/Linux/macOS.
