feat: add svelte web workspace shell

apps/web/src/app/App.svelte

@@ -0,0 +1,30 @@
+<script lang="ts">
+  import ProjectDashboard from '../features/projects/ProjectDashboard.svelte';
+  import ServerLogin from '../features/auth/ServerLogin.svelte';
+
+  let apiBase = localStorage.getItem('apiBase') ?? 'http://localhost:8080';
+
+  function handleServerChange(event: CustomEvent<{ apiBase: string }>) {
+    apiBase = event.detail.apiBase;
+    localStorage.setItem('apiBase', apiBase);
+  }
+</script>
+
+<main class="shell">
+  <aside class="sidebar">
+    <h1>项目工作台</h1>
+    <ServerLogin {apiBase} on:serverChange={handleServerChange} />
+  </aside>
+
+  <section class="workspace">
+    <ProjectDashboard
+      summary={{
+        project_id: 1,
+        pending_inbox_count: 0,
+        open_task_count: 0,
+        recent_note_count: 0,
+        recent_session_count: 0,
+      }}
+    />
+  </section>
+</main>