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/stores/useFilesViewTabsStore.ts

@@ -2,6 +2,7 @@ import { create } from 'zustand';
 import { devtools, persist } from 'zustand/middleware';
 
 import { createDeferredSafeJSONStorage } from './utils/safeStorage';
+import { getRuntimeKey } from '@/lib/runtime-switch';
 
 type RootTabsState = {
   openPaths: string[];
@@ -12,6 +13,8 @@ type RootTabsState = {
 
 type FilesViewTabsState = {
   byRoot: Record<string, RootTabsState>;
+  activeRuntimeKey: string;
+  runtimeSnapshots: Record<string, { byRoot: Record<string, RootTabsState>; updatedAt: number }>;
 };
 
 type FilesViewTabsActions = {
@@ -24,10 +27,18 @@ type FilesViewTabsActions = {
   toggleExpandedPath: (root: string, path: string) => void;
   expandPath: (root: string, path: string) => void;
   expandPaths: (root: string, paths: string[]) => void;
+  resetForRuntimeSwitch: (runtimeKey: string) => void;
 };
 
 export type FilesViewTabsStore = FilesViewTabsState & FilesViewTabsActions;
 
+const MAX_ROOTS = 20;
+const MAX_RUNTIME_SNAPSHOTS = 8;
+const MAX_OPEN_PATHS_PER_ROOT = 50;
+const MAX_EXPANDED_PATHS_PER_ROOT = 500;
+const MAX_PATH_LENGTH = 4096;
+const ROOT_TTL_MS = 90 * 24 * 60 * 60_000;
+
 const normalizePath = (value: string): string => {
   if (!value) return '';
 
@@ -90,14 +101,16 @@ const sanitizeByRoot = (input: unknown): Record<string, RootTabsState> => {
       ? Array.from(new Set(state.openPaths
         .filter((value): value is string => typeof value === 'string')
         .map((value) => normalizePath(value))
-        .filter((value) => isPathWithinRoot(value, root))))
+        .filter((value) => value.length <= MAX_PATH_LENGTH && isPathWithinRoot(value, root))))
+        .slice(-MAX_OPEN_PATHS_PER_ROOT)
       : [];
 
     const expandedPaths = Array.isArray(state.expandedPaths)
       ? Array.from(new Set(state.expandedPaths
         .filter((value): value is string => typeof value === 'string')
         .map((value) => normalizePath(value))
-        .filter((value) => isPathWithinRoot(value, root))))
+        .filter((value) => value.length <= MAX_PATH_LENGTH && isPathWithinRoot(value, root))))
+        .slice(-MAX_EXPANDED_PATHS_PER_ROOT)
       : [];
 
     const selectedPathCandidate = typeof state.selectedPath === 'string'
@@ -111,6 +124,7 @@ const sanitizeByRoot = (input: unknown): Record<string, RootTabsState> => {
     const touchedAt = typeof state.touchedAt === 'number' && Number.isFinite(state.touchedAt)
       ? state.touchedAt
       : Date.now();
+    if (Date.now() - touchedAt > ROOT_TTL_MS) continue;
 
     const existing = next[root];
     if (existing) {
@@ -134,7 +148,7 @@ const sanitizeByRoot = (input: unknown): Record<string, RootTabsState> => {
     };
   }
 
-  return next;
+  return clampRoots(next, MAX_ROOTS);
 };
 
 const clampRoots = (byRoot: Record<string, RootTabsState>, maxRoots: number): Record<string, RootTabsState> => {
@@ -163,6 +177,22 @@ export const useFilesViewTabsStore = create<FilesViewTabsStore>()(
     persist(
       (set, get) => ({
         byRoot: {},
+        activeRuntimeKey: getRuntimeKey(),
+        runtimeSnapshots: {},
+
+        resetForRuntimeSwitch: (runtimeKey) => {
+          set((state) => {
+            const runtimeSnapshots = {
+              ...state.runtimeSnapshots,
+              [state.activeRuntimeKey]: { byRoot: sanitizeByRoot(state.byRoot), updatedAt: Date.now() },
+            };
+            return {
+              activeRuntimeKey: runtimeKey,
+              runtimeSnapshots,
+              byRoot: sanitizeByRoot(runtimeSnapshots[runtimeKey]?.byRoot),
+            };
+          });
+        },
 
         addOpenPath: (root, path, options) => {
           const normalizedRoot = normalizePath((root || '').trim());
@@ -189,7 +219,7 @@ export const useFilesViewTabsStore = create<FilesViewTabsStore>()(
                 selectedPath: nextSelectedPath,
               },
             };
-            return { byRoot: clampRoots(byRoot, 20) };
+            return { byRoot: clampRoots(byRoot, MAX_ROOTS) };
           });
         },
 
@@ -225,7 +255,7 @@ export const useFilesViewTabsStore = create<FilesViewTabsStore>()(
                 touchedAt: Date.now(),
               },
             };
-            return { byRoot: clampRoots(byRoot, 20) };
+            return { byRoot: clampRoots(byRoot, MAX_ROOTS) };
           });
         },
 
@@ -267,7 +297,7 @@ export const useFilesViewTabsStore = create<FilesViewTabsStore>()(
               },
             };
 
-            return { byRoot: clampRoots(byRoot, 20) };
+            return { byRoot: clampRoots(byRoot, MAX_ROOTS) };
           });
         },
 
@@ -304,7 +334,7 @@ export const useFilesViewTabsStore = create<FilesViewTabsStore>()(
               },
             };
 
-            return { byRoot: clampRoots(byRoot, 20) };
+            return { byRoot: clampRoots(byRoot, MAX_ROOTS) };
           });
         },
 
@@ -334,7 +364,7 @@ export const useFilesViewTabsStore = create<FilesViewTabsStore>()(
                 selectedPath: normalizedPath,
               },
             };
-            return { byRoot: clampRoots(byRoot, 20) };
+            return { byRoot: clampRoots(byRoot, MAX_ROOTS) };
           });
         },
 
@@ -383,7 +413,7 @@ export const useFilesViewTabsStore = create<FilesViewTabsStore>()(
                 expandedPaths: nextExpandedPaths,
               },
             };
-            return { byRoot: clampRoots(byRoot, 20) };
+            return { byRoot: clampRoots(byRoot, MAX_ROOTS) };
           });
         },
 
@@ -410,7 +440,7 @@ export const useFilesViewTabsStore = create<FilesViewTabsStore>()(
                 expandedPaths: [...current.expandedPaths, normalizedPath],
               },
             };
-            return { byRoot: clampRoots(byRoot, 20) };
+            return { byRoot: clampRoots(byRoot, MAX_ROOTS) };
           });
         },
 
@@ -444,25 +474,49 @@ export const useFilesViewTabsStore = create<FilesViewTabsStore>()(
                 expandedPaths: [...current.expandedPaths, ...newPaths],
               },
             };
-            return { byRoot: clampRoots(byRoot, 20) };
+            return { byRoot: clampRoots(byRoot, MAX_ROOTS) };
           });
         },
       }),
       {
         name: 'files-view-tabs-store',
-        version: 2,
+        version: 3,
         storage: createDeferredSafeJSONStorage(),
-        migrate: (persistedState) => {
-          if (!persistedState || typeof persistedState !== 'object') {
-            return { byRoot: {} };
+        migrate: (persistedState, version) => {
+          if (version < 3 || !persistedState || typeof persistedState !== 'object') {
+            return { byRoot: {}, activeRuntimeKey: getRuntimeKey(), runtimeSnapshots: {} };
           }
-
-          const rawByRoot = (persistedState as { byRoot?: unknown }).byRoot;
+          return persistedState;
+        },
+        partialize: (state) => {
+          const currentSnapshots = {
+            ...state.runtimeSnapshots,
+            [state.activeRuntimeKey]: { byRoot: sanitizeByRoot(state.byRoot), updatedAt: Date.now() },
+          };
+          const runtimeSnapshots = Object.fromEntries(Object.entries(currentSnapshots)
+            .sort(([, left], [, right]) => right.updatedAt - left.updatedAt)
+            .slice(0, MAX_RUNTIME_SNAPSHOTS)
+            .map(([runtimeKey, snapshot]) => [runtimeKey, {
+              byRoot: sanitizeByRoot(snapshot.byRoot),
+              updatedAt: snapshot.updatedAt,
+            }]));
+          return { activeRuntimeKey: state.activeRuntimeKey, runtimeSnapshots };
+        },
+        merge: (persistedState, currentState) => {
+          const persisted = persistedState && typeof persistedState === 'object'
+            ? persistedState as Partial<FilesViewTabsState>
+            : {};
+          const runtimeSnapshots = persisted.runtimeSnapshots && typeof persisted.runtimeSnapshots === 'object'
+            ? persisted.runtimeSnapshots
+            : {};
+          const activeRuntimeKey = getRuntimeKey();
           return {
-            byRoot: sanitizeByRoot(rawByRoot),
+            ...currentState,
+            activeRuntimeKey,
+            runtimeSnapshots,
+            byRoot: sanitizeByRoot(runtimeSnapshots[activeRuntimeKey]?.byRoot),
           };
         },
-        partialize: (state) => ({ byRoot: sanitizeByRoot(state.byRoot) }),
       }
     ),
     { name: 'files-view-tabs-store' }