perf: overhaul session loading, caching, and runtime isolation (#2360)

Improve OpenChamber responsiveness under large session workloads while fixing
cache, synchronization, and persistence correctness across runtimes, projects,
directories, and worktrees.

- prioritize selected and visible sessions during bootstrap and defer
  non-critical enrichment work
- reduce redundant message loading, event processing, store publication, and
  hidden sidebar work
- prevent stale session and message requests from overwriting newer
  authoritative state
- preserve existing data when authoritative fetches fail instead of treating
  failures as successful empty responses
- scope session materialization, messages, drafts, queues, todos, pins,
  permissions, folders, tabs, Git state, and pull request data by runtime and
  directory identity
- harden runtime switching, reconnect, cleanup, mutation reconciliation, and
  persisted-state ordering
- preserve live subagent Task linkage when metadata arrives after an older
  message request or while streaming parts are suspended
- coalesce overlapping tail refreshes without losing newer refresh demand
- improve cold-session loading by moving deferrable work out of the critical
  bootstrap path
- isolate URL authentication, mobile credentials, native secrets, and other
  runtime-owned state across endpoint changes
- bound long-lived caches and remove avoidable allocations from event and
  rendering hot paths
- limit virtualization to archive collections where it improves rendering
  without disrupting active sidebar layout
- stabilize session folders, pin ordering, expanded state, and persisted
  sidebar behavior
- open skill files through the same secure editor and outside-workspace grant
  flow used by file navigation, including worktree sessions
- expand regression coverage for stale completions, runtime collisions,
  reconnect behavior, persistence races, authoritative empty results, and
  subagent refresh ordering
- document the updated synchronization, cache ownership, performance, and
  runtime-isolation invariants

packages/ui/src/sync/event-reducer.ts

@@ -217,6 +217,21 @@ export function applyDirectoryEvent(
     onSetSessionTodo?: (sessionID: string, todos: Todo[] | undefined) => void
   },
 ): DirectoryEventResult {
+  const markSessionEvent = (sessionID: string, deleted: boolean) => {
+    const revision = (draft.sessionRevision ?? 0) + 1
+    draft.sessionRevision = revision
+    draft.sessionListSource = "live"
+    draft.sessionEventRevision = draft.sessionEventRevision ?? {}
+    draft.sessionDeletedRevision = draft.sessionDeletedRevision ?? {}
+    if (deleted) {
+      draft.sessionDeletedRevision[sessionID] = revision
+      delete draft.sessionEventRevision[sessionID]
+    } else {
+      draft.sessionEventRevision[sessionID] = revision
+      delete draft.sessionDeletedRevision[sessionID]
+    }
+  }
+
   switch (event.type) {
     case "server.instance.disposed": {
       callbacks?.onRefresh?.("")
@@ -237,6 +252,7 @@ export function applyDirectoryEvent(
         trimSessions(draft)
         if (!info.parentID) draft.sessionTotal += 1
       }
+      markSessionEvent(info.id, false)
       return true
     }
 
@@ -256,6 +272,7 @@ export function applyDirectoryEvent(
         if (result.found) sessions.splice(result.index, 1)
         cleanupSessionCaches(draft, info.id, callbacks?.onSetSessionTodo)
         if (!info.parentID) draft.sessionTotal = Math.max(0, draft.sessionTotal - 1)
+        markSessionEvent(info.id, true)
         return true
       }
 
@@ -265,16 +282,21 @@ export function applyDirectoryEvent(
         sessions.splice(result.index, 0, info)
         trimSessions(draft)
       }
+      markSessionEvent(info.id, false)
       return true
     }
 
     case "session.deleted": {
-      const info = (event.properties as { info: Session }).info
       const sessions = draft.session
-      const result = Binary.search(sessions, info.id, (s) => s.id)
+      const props = event.properties as { info?: Session; sessionID?: string }
+      const sessionID = props.info?.id ?? props.sessionID
+      if (!sessionID) return false
+      const result = Binary.search(sessions, sessionID, (s) => s.id)
+      const info = props.info ?? (result.found ? sessions[result.index] : undefined)
       if (result.found) sessions.splice(result.index, 1)
-      cleanupSessionCaches(draft, info.id, callbacks?.onSetSessionTodo)
-      if (!info.parentID) draft.sessionTotal = Math.max(0, draft.sessionTotal - 1)
+      cleanupSessionCaches(draft, sessionID, callbacks?.onSetSessionTodo)
+      if (!info?.parentID) draft.sessionTotal = Math.max(0, draft.sessionTotal - 1)
+      markSessionEvent(sessionID, true)
       return true
     }