feat(analytics): add optional Aptabase event tracking UI

Integrate Aptabase analytics via a Tauri plugin and add a privacy
notice flow plus a settings dialog to control whether anonymous
usage events are sent. The app now tracks key user actions while
ensuring analytics never blocks core Git operations.

- Add analytics tracking helper and Aptabase plugin wiring
- Persist analytics consent in localStorage and gate tracking
- Introduce notice and settings dialogs, plus new event calls

src/lib/TitleBar.svelte

@@ -2,7 +2,7 @@
   import { onDestroy, onMount } from "svelte";
   import { getVersion } from "@tauri-apps/api/app";
   import { getCurrentWindow } from "@tauri-apps/api/window";
-  import { CloudDownload, Download, FolderOpen, GitBranch, GitCompare, LoaderCircle, Minus, RefreshCw, Search, Upload, X } from "@lucide/svelte";
+  import { CloudDownload, Download, FolderOpen, GitBranch, GitCompare, LoaderCircle, Minus, RefreshCw, Search, Settings, Upload, X } from "@lucide/svelte";
 
   export let branch: string = "";
   export let ahead: number = 0;
@@ -21,6 +21,7 @@
   export let onCompare: () => void = () => {};
   export let onOpenInExplorer: () => void = () => {};
   export let onToggleAutoRefresh: () => void = () => {};
+  export let onOpenSettings: () => void = () => {};
 
   const win = getCurrentWindow();
   let isMaximized = false;
@@ -198,6 +199,16 @@
         />
         <span class="tb-action-label">Auto</span>
       </button>
+
+      <button
+        class="tb-action"
+        onclick={onOpenSettings}
+        title="Settings"
+        aria-label="Settings"
+      >
+        <Settings size={14} aria-hidden="true" />
+        <span class="tb-action-label">Settings</span>
+      </button>
     </div>
 
     <div class="titlebar-divider" aria-hidden="true"></div>