feat: add About dialog with version, author, and license info

Co-authored-by: Cursor <cursoragent@cursor.com>

src/lib/components/StatusBar.svelte

@@ -1,6 +1,17 @@
 <script lang="ts">
+  import { getVersion } from '@tauri-apps/api/app';
   import { session, upgradePreview } from '$lib/stores/videoSession.svelte';
 
+  let { onOpenAbout }: { onOpenAbout?: () => void } = $props();
+
+  let appVersion = $state('');
+
+  $effect(() => {
+    getVersion().then((v) => {
+      appVersion = v;
+    });
+  });
+
   let previewPercent = $derived(Math.round(session.previewProgress * 100));
   let exportPercent = $derived(Math.round(session.exportProgress * 100));
 
@@ -42,6 +53,11 @@
   {:else}
     <span class="status-text">Ready</span>
   {/if}
+  {#if appVersion}
+    <button class="version-btn" onclick={() => onOpenAbout?.()} title="About GUI Video Clipper">
+      v{appVersion}
+    </button>
+  {/if}
 </div>
 
 <style>
@@ -91,4 +107,21 @@
     background: var(--accent, #89b4fa);
     color: var(--bg-primary, #1e1e2e);
   }
+
+  .version-btn {
+    margin-left: auto;
+    background: none;
+    border: none;
+    color: var(--text-muted);
+    font-size: 11px;
+    font-family: var(--font-mono);
+    padding: 2px 6px;
+    cursor: pointer;
+    border-radius: 3px;
+  }
+
+  .version-btn:hover {
+    background: var(--bg-secondary);
+    color: var(--text-secondary);
+  }
 </style>