fix(file-tree): keep aux-panel tree in sync with filesystem changes

Deep directories (beyond the workspace snapshot's depth limit) relied on
a lazy-loaded override cache that was never invalidated, so agent-created
files, in-app deletes / renames / rollbacks, and external changes inside
expanded deep folders stayed invisible until the folder was reopened.

Propagate watcher `changed_paths` through the delta envelope and fire a
Meta event whenever FS activity doesn't alter the tree/git snapshots, so
the frontend can surgically invalidate affected cache entries and
re-fetch. Manual refresh (Reload from disk) clears the cache and
re-hydrates still-expanded deep dirs through the same path. Replayed
deltas after reconnect are forwarded to the same listeners.

Also split the combined workspace-state effect into tree / git / status
slices so unrelated state transitions (e.g. the 'resyncing' flip during
a refresh) no longer rebuild the entire node tree and cause a flash.

src/lib/types.ts

@@ -879,6 +879,7 @@ export interface WorkspaceDeltaEnvelope {
   kind: "fs_delta" | "git_delta" | "meta" | "resync_hint" | string
   payload: WorkspaceDelta[]
   requires_resync: boolean
+  changed_paths?: string[]
 }
 
 export interface WorkspaceStateEvent {
@@ -888,6 +889,7 @@ export interface WorkspaceStateEvent {
   kind: "fs_delta" | "git_delta" | "meta" | "resync_hint" | string
   payload: WorkspaceDelta[]
   requires_resync: boolean
+  changed_paths?: string[]
 }
 
 export interface WorkspaceSnapshotResponse {