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/components/AppSettingsDialog.svelte

@@ -0,0 +1,68 @@
+<script lang="ts">
+  import { Check, Settings, X } from "@lucide/svelte";
+  import type { AnalyticsSettings } from "../types";
+
+  interface Props {
+    analytics: AnalyticsSettings;
+    onSave: (settings: AnalyticsSettings) => void;
+    onClose: () => void;
+  }
+
+  let { analytics, onSave = () => {}, onClose = () => {} }: Props = $props();
+
+  let analyticsEnabled = $state(true);
+
+  $effect(() => {
+    analyticsEnabled = analytics.enabled;
+  });
+
+  function save() {
+    onSave({
+      ...analytics,
+      enabled: analyticsEnabled,
+      noticeSeen: true,
+    });
+  }
+</script>
+
+<div class="dialog-backdrop" role="presentation">
+  <div class="dialog app-settings-dialog" role="dialog" aria-modal="true" aria-label="Settings" tabindex="-1">
+    <header class="dialog-header">
+      <div>
+        <span class="eyebrow">GitLite</span>
+        <h2 class="dialog-title">Settings</h2>
+      </div>
+      <button class="dialog-close" type="button" onclick={onClose} title="Close">
+        <X size={18} aria-hidden="true" />
+      </button>
+    </header>
+
+    <form class="app-settings-form" onsubmit={(event) => { event.preventDefault(); save(); }}>
+      <section class="settings-section">
+        <header>
+          <Settings size={16} aria-hidden="true" />
+          <div>
+            <span class="eyebrow">Analytics</span>
+            <h3>Anonymous usage analytics</h3>
+          </div>
+        </header>
+
+        <label class="settings-toggle-row">
+          <input type="checkbox" bind:checked={analyticsEnabled} />
+          <span>
+            <strong>Allow anonymous Aptabase events</strong>
+            <small>No repository paths, remotes, branches, commit messages, file names, diffs, credentials, or code are sent.</small>
+          </span>
+        </label>
+      </section>
+
+      <div class="new-branch-actions">
+        <button class="btn-secondary" type="button" onclick={onClose}>Cancel</button>
+        <button class="btn-primary" type="submit">
+          <Check size={16} aria-hidden="true" />
+          Save
+        </button>
+      </div>
+    </form>
+  </div>
+</div>