feat: handle PostCompact hook event (#225)

Parses [PostCompact Hook] from stderr, emits claude:post-compact, shows
a toast notification, and briefly sets the character to success state.

src/lib/tauri.ts

@@ -10,6 +10,7 @@ import type {
   ConnectionStatus,
   ElicitationEvent,
   PermissionPromptEvent,
+  PostCompactEvent,
   StopFailureEvent,
   UserQuestionEvent,
 } from "$lib/types/messages";
@@ -659,6 +660,12 @@ export async function initializeTauriListeners() {
     toastStore.addError(message);
   });
   unlisteners.push(stopFailureUnlisten);
+
+  const postCompactUnlisten = await listen<PostCompactEvent>("claude:post-compact", () => {
+    toastStore.addInfo("Context compacted", "🗜️");
+    characterState.setTemporaryState("success", 2000);
+  });
+  unlisteners.push(postCompactUnlisten);
 }
 
 export function cleanupTauriListeners() {

src/lib/types/messages.ts

@@ -182,6 +182,11 @@ export interface StopFailureEvent {
   conversation_id?: string;
 }
 
+export interface PostCompactEvent {
+  session_id?: string;
+  conversation_id?: string;
+}
+
 export type ConnectionStatus = "disconnected" | "connecting" | "connected" | "error";
 
 export interface Attachment {