Implementing app search feature (#1302)

This PR implements app search feature and addresses the issue #1182.
    
<!-- This is an auto-generated description by cubic. -->
---

## Summary by cubic
Adds a fast app search with a command-style dialog so users can find
apps by name or chat content and jump to them quickly. Implements the
search experience requested in #1182.

- New Features
- Search dialog (Ctrl+K or “Search Apps” button) with result snippets
from matching chat titles/messages.
- Searches across app names, chat titles, and message content;
case-insensitive; supports partial matches; empty query lists all apps.
  - Selecting a result navigates to the app and closes the dialog.
- New IPC endpoint search-app with Zod-validated results, debounced
React Query hook, and preload allowlist update.
- Added E2E tests for dialog open/close, shortcuts, matching behavior,
empty state, and navigation.

<!-- End of auto-generated description by cubic. -->

src/ipc/ipc_client.ts

@@ -5,6 +5,7 @@ import {
   type UserSettings,
   type ContextPathResults,
   ChatSearchResultsSchema,
+  AppSearchResultsSchema,
 } from "../lib/schemas";
 import type {
   AppOutput,
@@ -66,6 +67,7 @@ import type {
 import type { Template } from "../shared/templates";
 import type {
   AppChatContext,
+  AppSearchResult,
   ChatSearchResult,
   ProposalResult,
 } from "@/lib/schemas";
@@ -312,6 +314,17 @@ export class IpcClient {
     return this.ipcRenderer.invoke("list-apps");
   }
 
+  // Search apps by name
+  public async searchApps(searchQuery: string): Promise<AppSearchResult[]> {
+    try {
+      const data = await this.ipcRenderer.invoke("search-app", searchQuery);
+      return AppSearchResultsSchema.parse(data);
+    } catch (error) {
+      showError(error);
+      throw error;
+    }
+  }
+
   public async readAppFile(appId: number, filePath: string): Promise<string> {
     return this.ipcRenderer.invoke("read-app-file", {
       appId,