fix: forward hook event data to notifications

The server was dropping the `data` field from hook-event POST requests,
so notifications always showed generic messages. Now forwards tool name,
command, question text, and reason to the frontend.

Notifications now show:
- permission_prompt: "Bash: docker push prod:latest"
- elicitation_dialog: "Merge PR #42 to main?"
- idle_prompt: custom message if provided
- stop: reason if provided

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/types.ts

@@ -382,6 +382,8 @@ export interface HookEventRequest {
   event: HookEventType;
   /** Session ID from CLAUDEMAN_SESSION_ID env var */
   sessionId: string;
+  /** Additional event data (tool name, command, question, etc.) */
+  data?: Record<string, unknown>;
 }
 
 // ========== API Response Types ==========