Redesign Resources screen: template panel, subscriptions, hover states, and callback architecture

- Rename ResourceTemplateInput to ResourceTemplatePanel with panel layout
  (title header, URI with live variable preview, labeled inputs, Read Resource button)
- ResourceTemplatePanel manages its own variable state via useState;
  single onReadResource(uri) callback returns fully resolved URI
- Extract ResourceSubscribedItem group component with name, timestamp, and
  subtle Unsubscribe button
- Add hover state to listItem variant via theme classNames + App.css pseudo-selector
- Add Refresh button to ResourcePreviewPanel
- Refactor ResourcesScreen callbacks: onSelectUri, onSelectTemplate,
  onReadResource, onSubscribeResource, onUnsubscribeResource replace
  per-item onClick/onUnsubscribe props; screen wires callbacks to children
- Define data-only types (ResourceItem, TemplateListItem, SubscriptionItem,
  SelectedResource, SelectedTemplate) separating data from callbacks
- Extract named .withProps() subcomponents (FooterRow, AnnotationGroup,
  ActionGroup, Spacer) for AGENTS.md compliance
- Update all stories (ResourceTemplatePanel, ResourcesScreen, ConnectedView)

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

clients/web/src/components/groups/ResourcePreviewPanel/ResourcePreviewPanel.stories.tsx

@@ -6,6 +6,7 @@ const meta: Meta<typeof ResourcePreviewPanel> = {
   title: "Groups/ResourcePreviewPanel",
   component: ResourcePreviewPanel,
   args: {
+    onRefresh: fn(),
     onSubscribe: fn(),
     onUnsubscribe: fn(),
   },