* fix(pipeline): distinguish transport switch from real disconnect
WS_FALLBACK errors (e.g. ready timeout → SSE fallback) are transport
switches, not disconnections. No events are lost because lastEventId is
preserved across the switch.
Previously, every WS timeout triggered onDisconnect → onReconnect with a
full resyncDirectoryAfterReconnect, which:
- Missed idle parent sessions in candidate selection (root cause 1)
- Could overwrite in-flight SSE state with stale fetch data (root cause 4)
- Caused isConnected to flash false→true
Now: WS_FALLBACK fires onTransportSwitch (sets isConnected only).
Real disconnections (heartbeat timeout, network error) still fire the
full onDisconnect → onReconnect → resync cycle.
* fix(sync): relationship-aware reconnect with merge-not-replace
Two changes to resyncDirectoryAfterReconnect:
1. Candidate selection now also includes parent sessions of any child
sessions in the directory. Previously, if a child completed during
the disconnect gap (busy→idle), neither child nor parent was selected
because both appeared idle. The parent's task tool part would remain
permanently stale.
2. Parent resync merges parts instead of replacing. Previously, the
resync deleted parts for messages not in the fetch snapshot, which
could erase parts delivered by SSE events that arrived between the
fetch and the setState. Now only parts for messages in the snapshot
are overwritten; everything else is preserved.
* fix(sync): demand-load child session messages on access
Bootstrap only loads session metadata — messages are populated
exclusively by SSE events. When a user navigates to an old session
that spawned subagents, child session messages were never in the store.
Add useEnsureSessionMessages hook that detects this gap (session exists
in state.session but state.message[sessionID] is absent) and triggers a
background API fetch to load messages and parts.
ToolPart already calls useSessionMessageRecords(taskSessionId) which
returns empty when not loaded. Now it also calls useEnsureSessionMessages
to populate the store on first access.
* fix(sync): unmount-safe parent resync when child session goes idle
When a child session transitions to idle (completes), the sync layer
now schedules a targeted parts repair for the parent session's task
tool part. Previously this only happened when the ToolPart component
was mounted and had observed the child being active (taskChildSeenActive).
This covers:
- User navigated away while child was running
- App restarted with active subagent sessions
- SSE reconnect where child completed during disconnect
Uses the existing repairSessionParts mechanism with its 5s cooldown
to avoid redundant fetches.
* fix: type-check fixes for sync-layer parent resync
Fix TypeScript errors in Fix 5 implementation:
- Convert currentSessionId from null to undefined for resolveFallbackTaskSessionId
- Add default empty string for dir parameter in getScopedSdkClient
- Use explicit sessionID parameter for scopedClient.session.messages
All type-checks now pass.
* fix(sync): address PR review feedback on deduplication
- Use enqueuePartsRepair for session.idle parent resync instead of
direct repairSessionParts call. enqueuePartsRepair already has a 5s
cooldown to prevent redundant parallel API calls when multiple child
sessions go idle concurrently.
- Move useEnsureSessionMessages loading guard from component-scoped
React.useRef to a module-level Set keyed by directory:sessionID.
Prevents parallel fetches when multiple ToolPart instances mount
for the same child session.
* fix(sync): add missing semicolon on useEnsureSessionMessages call
Address Greptile P2 review comment on ToolPart.tsx:1931.
jwcrystal
17dd526731