Phase 2: device registry, dashboard cards, manual lock/unlock, audit

- Device registry: add/edit name, child and platform, persisted in devices.
- Stable per-device topic derived from name + id, unchanged by renames.
- Desired state persisted in state; timed locks expire and are audited.
- Dashboard cards: name, child, platform, status dot, state and time left.
- Manual lock/unlock forms with CSRF; every change appends to audit (FR-15).
- Append-only activity list on the dashboard. No hard deletes (rule 10).
- Store and handler tests; version bumped to 0.2.0-phase2.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

internal/web/templates/dashboard.html

@@ -27,21 +27,39 @@
   <main class="container">
     <header class="page-head">
       <h1 class="heading-1">Dashboard</h1>
-      <p class="page-head__sub">Phase 1 skeleton — the Control Service is up and answering.</p>
+      <p class="page-head__sub">Lock or unlock a device. State is saved in SQLite and written to the audit log.</p>
     </header>
 
+    {{if .Flash}}<p class="flash flash--ok" role="status">{{.Flash}}</p>{{end}}
+    {{if .ErrMsg}}<p class="flash flash--error" role="alert">{{.ErrMsg}}</p>{{end}}
+
     {{template "status.html" .}}
 
     <section class="section" aria-labelledby="devices-title">
       <div class="section__head">
         <h2 id="devices-title" class="heading-2">Devices</h2>
-        <span class="category-pill"><span class="dot dot--faint"></span>0 registered</span>
+        <div class="section__actions">
+          <span class="category-pill"><span class="dot dot--faint"></span>{{len .Devices}} registered</span>
+          <a class="button-primary" href="/devices/new">Add device</a>
+        </div>
       </div>
-      <div class="empty-state">
-        <p class="empty-state__title">No devices yet</p>
-        <p class="empty-state__body">Device registration arrives in Phase 2. Until then the
-          dashboard, session login and <code>/health</code> are the working pieces.</p>
+      {{if .Devices}}
+        {{template "device-cards.html" .}}
+      {{else}}
+        <div class="empty-state">
+          <p class="empty-state__title">No devices yet</p>
+          <p class="empty-state__body">Add Harry's phone or Finn's computer to give it a name,
+            a child, and a platform. Nothing is enforced until a later phase.</p>
+        </div>
+      {{end}}
+    </section>
+
+    <section class="section" aria-labelledby="audit-title">
+      <div class="section__head">
+        <h2 id="audit-title" class="heading-2">Activity</h2>
+        <span class="category-pill">append-only audit</span>
       </div>
+      {{template "audit-list.html" .}}
     </section>
   </main>