fix(sync): preserve pending questions across session switch and directory eviction (closes #918) (#1103)

* fix(sync): preserve pending questions across session switch and directory eviction

Closes #918, completes the gap left by #909.

The 'agent question disappears after switching session / coming back
later' bug had two root causes that #909 only partially addressed:

1. Directory-eviction TTL (20 min) silently dropped child stores that
   held pending questions/permissions. The discard wasn't gated on
   in-flight blocking-request state, so any 'question.asked' event
   that arrived during the eviction-then-rehydrate window was routed
   to a non-existent store and silently lost.

2. PR #909 re-fetches listPendingQuestions/Permissions only on SSE
   reconnect. Switching sessions within the same socket — including
   navigating back to a directory whose child store was rebuilt after
   eviction — left the UI relying on store state that may have missed
   events that fired while a different session was active.

Three edits, in src/sync:

- eviction.ts / types.ts / child-store.ts: add hasPendingBlockingRequests
  to EvictPlan + DisposeCheck and never evict a directory whose store
  carries a non-empty state.question or state.permission record.
- sync-context.tsx: extract resyncBlockingRequestsForDirectory from the
  reconnect path and call it on currentSessionId changes (debounced
  250ms), reusing PR #909's signature-based merge so concurrent SSE
  updates aren't clobbered.
- __tests__/eviction.test.ts, __tests__/session-switch-resync.test.ts:
  new unit coverage for the eviction guard and resync semantics
  (deduped fetch per switch, in-flight SSE preservation, stale entry
  cleanup, unknown-session filtering).

* fix(sync): refresh store before blocking request resync

---------

Co-authored-by: Alexander Busse <alex@ableph.net>
Co-authored-by: Bohdan Triapitsyn <artmore@protonmail.com>

packages/ui/src/sync/child-store.ts

@@ -1,7 +1,7 @@
 import { create, type StoreApi } from "zustand"
 import type { DirState, State } from "./types"
 import { INITIAL_STATE, MAX_DIR_STORES, DIR_IDLE_TTL_MS } from "./types"
-import { pickDirectoriesToEvict, canDisposeDirectory } from "./eviction"
+import { pickDirectoriesToEvict, canDisposeDirectory, hasPendingBlockingRequests } from "./eviction"
 import { readDirCache, persistVcs, persistProjectMeta, persistIcon } from "./persist-cache"
 
 export type DirectoryStore = State & {
@@ -123,6 +123,7 @@ export class ChildStoreManager {
         pinned: this.pinned(directory),
         booting: this.isBooting?.(directory) ?? false,
         loadingSessions: this.isLoadingSessions?.(directory) ?? false,
+        hasPendingBlockingRequests: this.hasPendingBlockingRequestsForDirectory(directory),
       })
     ) {
       return false
@@ -150,12 +151,17 @@ export class ChildStoreManager {
       max: MAX_DIR_STORES,
       ttl: DIR_IDLE_TTL_MS,
       now: Date.now(),
+      hasPendingBlockingRequests: (dir) => this.hasPendingBlockingRequestsForDirectory(dir),
     }).filter((d) => d !== skip)
     for (const directory of list) {
       this.disposeDirectory(directory)
     }
   }
 
+  hasPendingBlockingRequestsForDirectory(directory: string): boolean {
+    return hasPendingBlockingRequests(this.children.get(directory)?.getState())
+  }
+
   /** Apply a state mutation to a directory's store */
   update(directory: string, fn: (state: State) => Partial<State>) {
     const store = this.children.get(directory)