fix(hooks): add session-notification to disabled_hooks with race/memory fixes

- Add session-notification to HookNameSchema and schema.json
- Integrate session-notification into disabled_hooks conditional creation
- Fix race condition with version-based invalidation
- Fix memory leak with maxTrackedSessions cleanup
- Add missing activity event types (message.created, tool.execute.*)
- Document disabled_hooks configuration in README

🤖 GENERATED WITH ASSISTANCE OF [OhMyOpenCode](https://github.com/code-yeongyu/oh-my-opencode)

assets/oh-my-opencode.schema.json

@@ -40,6 +40,7 @@
           "todo-continuation-enforcer",
           "context-window-monitor",
           "session-recovery",
+          "session-notification",
           "comment-checker",
           "grep-output-truncator",
           "directory-agents-injector",