When the computer sleeps and wakes, the SSE/WS event stream drops
silently. Messages appeared sent (optimistic insert) but never reached
the OpenCode server, and the user had no indication the system was
disconnected.
Three fixes:
1. Connection state tracking: add onDisconnect callback to the event
pipeline. Stream failures set isConnected=false in useConfigStore;
successful reconnect sets isConnected=true.
2. Send guard: optimisticSend, respondToPermission, and
respondToQuestion now check isConnected before making API calls,
throwing a clear error that surfaces as a toast to the user.
The /compact command also checks connection with error feedback.
3. Faster server recovery: add triggerHealthCheck() to the server
lifecycle and wire it into the WS event stream runtime. When the
upstream OpenCode connection fails, the server immediately checks
health and restarts if needed, instead of waiting up to 15s for
the periodic health check.