feat: add visual todo list panel

- Add TodoPanel component to display TodoWrite tool calls
- Create todos Svelte store to track todo state
- Emit todo-update Tauri event when TodoWrite is called
- Add todo button to status bar (next to session history)
- Display todos with status icons, progress bar, and completion count
- Real-time updates as I work through tasks

Closes #132

src/lib/components/StatusBar.svelte

@@ -23,6 +23,7 @@
   import { achievementProgress } from "$lib/stores/achievements";
   import { runningAgentCount } from "$lib/stores/agents";
   import SessionHistoryPanel from "./SessionHistoryPanel.svelte";
+  import TodoPanel from "./TodoPanel.svelte";
   import GitPanel from "./GitPanel.svelte";
   import ProfilePanel from "./ProfilePanel.svelte";
   import AgentMonitorPanel from "./AgentMonitorPanel.svelte";
@@ -49,6 +50,7 @@
   let showHelp = $state(false);
   let showKeyboardShortcuts = $state(false);
   let showSessionHistory = $state(false);
+  let showTodoPanel = $state(false);
   let showGitPanel = $state(false);
   let showProfile = $state(false);
   let showAgentMonitor = $state(false);
@@ -438,6 +440,20 @@
         />
       </svg>
     </button>
+    <button
+      onclick={() => (showTodoPanel = true)}
+      class="p-1 text-gray-500 icon-trans-hover"
+      title="Todo List"
+    >
+      <svg class="w-5 h-5" fill="none" stroke="currentColor" viewBox="0 0 24 24">
+        <path
+          stroke-linecap="round"
+          stroke-linejoin="round"
+          stroke-width="2"
+          d="M9 5H7a2 2 0 00-2 2v12a2 2 0 002 2h10a2 2 0 002-2V7a2 2 0 00-2-2h-2M9 5a2 2 0 002 2h2a2 2 0 002-2M9 5a2 2 0 012-2h2a2 2 0 012 2m-6 9l2 2 4-4"
+        />
+      </svg>
+    </button>
     <button
       onclick={() => (showGitPanel = true)}
       class="p-1 text-gray-500 icon-trans-hover"
@@ -673,6 +689,10 @@
   <SessionHistoryPanel onClose={() => (showSessionHistory = false)} />
 {/if}
 
+{#if showTodoPanel}
+  <TodoPanel onClose={() => (showTodoPanel = false)} />
+{/if}
+
 {#if showGitPanel}
   <GitPanel isOpen={showGitPanel} onClose={() => (showGitPanel = false)} />
 {/if}