feat: persist permission auto-accept on server (#2158)

Move per-session permission auto-accept policy ownership from the UI to the
OpenChamber server so enabled sessions continue running when clients disconnect
or the server restarts.

- persist explicit per-session policies in OpenChamber settings
- inherit the nearest explicit policy across subagent session hierarchies
- allow child sessions to opt out of an inherited parent policy
- immediately accept matching global and directory-scoped pending requests
- process future requests without requiring a connected UI client
- reconcile pending permissions after startup and event-stream reconnects
- deduplicate concurrent requests and retry transient reply failures
- synchronize policy updates across connected clients
- migrate existing browser-persisted policies to server storage
- suppress auto-accepted permission cards before they enter UI state
- show deduplicated permission toasts for inactive sessions
- preserve foreground-only permission handling in VS Code
- integrate directory-aware notification routing from main
- add coverage for persistence, inheritance, retries, reconciliation, pending
  requests, client hydration, and inactive-session toasts

packages/web/server/lib/notifications/DOCUMENTATION.md

@@ -45,7 +45,7 @@ This module provides notification message preparation utilities for the web serv
 - Returned API:
   - `maybeSendPushForTrigger(payload)`
 - Owns:
-  - completion/error/question/permission trigger routing
+  - completion/error/question/permission trigger routing; permission suppression consults the authoritative permission-auto-accept runtime
   - session parent cache for subtask suppression
   - template resolution and fallback behavior
   - native notification fanout and web push payload fanout