Feat v0.7.3 extension shell migration

Migrate Chat, Notes, and Schedules from legacy sw.shell.Topbar to the
v0.7.0 shell topbar contract (sw.shell.topbar.setTitle/setSlot),
eliminating double topbars on all extension surfaces.

- Chat v0.3.0: reactive slot for thread title + People button
- Notes v0.9.0: slot for New/Import/Graph buttons
- Schedules v0.2.0: reactive slot for count + New button
- 6 new shell-topbar runner tests (2 per surface)
- Headless E2E deferred to v0.7.5

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

packages/schedules/js/main.js

@@ -5,7 +5,7 @@
  * this surface talks directly to the core scheduled-tasks endpoints.
  *
  * SDK usage:
- *   sw.shell.Topbar  — standard navigation bar
+ *   sw.shell.topbar   — shell topbar API
  *   sw.ui.*          — primitive components
  *   sw.api.*         — raw REST calls to /api/v1/schedules
  */
@@ -39,7 +39,6 @@
   var { useState, useEffect, useCallback } = hooks;
   var { render } = preact;
   var { Button, FormField, Dialog, Spinner, Banner } = sw.ui;
-  var Topbar = sw.shell?.Topbar;
 
   // ── API helpers (core kernel endpoints) ────
   var API = '/api/v1/schedules';
@@ -365,6 +364,16 @@
 
     useEffect(function () { loadItems(); }, []);
 
+    // ── Shell topbar ───────────────────────────
+    useEffect(function () {
+      if (!sw.shell?.topbar) return;
+      sw.shell.topbar.setTitle('Schedules');
+      sw.shell.topbar.setSlot(html`
+        <span class="ext-schedules-count">${items.length} schedule${items.length !== 1 ? 's' : ''}</span>
+        <${Button} variant="primary" size="sm" onClick=${() => setEditing({})}>+ New Schedule<//>
+      `);
+    }, [items.length]);
+
     function handleSave() {
       setEditing(null);
       loadItems();
@@ -372,17 +381,6 @@
 
     return html`
       <div class="ext-schedules-app">
-        ${Topbar ? html`
-          <${Topbar} title="Schedules">
-            <span class="ext-schedules-count">${items.length} schedule${items.length !== 1 ? 's' : ''}</span>
-            <${Button} variant="primary" size="sm" onClick=${() => setEditing({})}>+ New Schedule<//>
-          <//>
-        ` : html`
-          <div class="ext-schedules-header">
-            <h1>Schedules</h1>
-            <${Button} variant="primary" size="sm" onClick=${() => setEditing({})}>+ New Schedule<//>
-          </div>
-        `}
 
         ${error && html`<${Banner} variant="danger" text=${error} />`}
 

packages/schedules/manifest.json

@@ -2,7 +2,7 @@
   "id": "schedules",
   "title": "Schedules",
   "type": "full",
-  "version": "0.1.0",
+  "version": "0.2.0",
   "tier": "browser",
   "author": "Armature",
   "icon": "⏰",