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/components/chat/ChatMessage.tsx

@@ -163,12 +163,8 @@ const ChatMessage: React.FC<ChatMessageProps> = ({
     const { currentTheme } = useThemeSystem();
     const messageContainerRef = React.useRef<HTMLDivElement | null>(null);
 
-    const currentSessionId = useSessionUIStore((s) => s.currentSessionId);
-
     const getAgentModelForSession = useSelectionStore((s) => s.getAgentModelForSession);
     const getSessionModelSelection = useSelectionStore((s) => s.getSessionModelSelection);
-    const revertToMessage = useSessionUIStore((s) => s.revertToMessage);
-    const forkFromMessage = useSessionUIStore((s) => s.forkFromMessage);
 
     streamPerfCount('ui.chat_message.render');
     if (isInActiveTurn) {
@@ -186,12 +182,6 @@ const ChatMessage: React.FC<ChatMessageProps> = ({
         }))
     );
 
-    React.useEffect(() => {
-        if (currentSessionId) {
-            MessageFreshnessDetector.getInstance().recordSessionStart(currentSessionId);
-        }
-    }, [currentSessionId]);
-
     const [copiedCode, setCopiedCode] = React.useState<string | null>(null);
     const [copiedMessage, setCopiedMessage] = React.useState(false);
     const [expandedTools, setExpandedTools] = React.useState<Set<string>>(() => readExpandedToolsCache(message.info.id));
@@ -580,8 +570,8 @@ const ChatMessage: React.FC<ChatMessageProps> = ({
     const shouldAnimateMessage = React.useMemo(() => {
         if (isUser) return false;
         const freshnessDetector = MessageFreshnessDetector.getInstance();
-        return freshnessDetector.shouldAnimateMessage(message.info, currentSessionId || message.info.sessionID);
-    }, [message.info, currentSessionId, isUser]);
+        return freshnessDetector.shouldAnimateMessage(message.info, message.info.sessionID);
+    }, [message.info, isUser]);
 
     const [hasStartedStreamingHeader, setHasStartedStreamingHeader] = React.useState(false);
 
@@ -794,14 +784,14 @@ const ChatMessage: React.FC<ChatMessageProps> = ({
 
     const handleRevert = React.useCallback(() => {
         if (!sessionId || !message.info.id) return;
-        revertToMessage(sessionId, message.info.id);
-    }, [sessionId, message.info.id, revertToMessage]);
+        useSessionUIStore.getState().revertToMessage(sessionId, message.info.id);
+    }, [sessionId, message.info.id]);
 
     // NEW: Fork handler
     const handleFork = React.useCallback(() => {
         if (!sessionId || !message.info.id) return;
-        forkFromMessage(sessionId, message.info.id);
-    }, [sessionId, message.info.id, forkFromMessage]);
+        useSessionUIStore.getState().forkFromMessage(sessionId, message.info.id);
+    }, [sessionId, message.info.id]);
 
     const handleToggleTool = React.useCallback((toolId: string) => {
         const isDefaultOpen = defaultOpenToolIds.has(toolId);