feat(apps): add AppListItem and AppDetailPanel groups (#1261) (#1273)

* feat(apps): add AppListItem and AppDetailPanel groups (#1261)

Two presentational groups for the upcoming AppsScreen.

AppListItem (clients/web/src/components/groups/AppListItem/):
- Props { tool, selected, onClick }
- Renders tool.icons[0] (sized sm) when present, label (title ?? name),
  two-line clamped description, and a trailing chevron affordance.
- Reuses ToolListItem's selected-state highlight (UnstyledButton bg via
  --mantine-primary-color-light).

AppDetailPanel (clients/web/src/components/groups/AppDetailPanel/):
- Props { tool, formValues, isOpening, onFormChange, onOpenApp }
- Layout: optional icon + title row, optional description, divider,
  SchemaForm bound to tool.inputSchema, full-width "Open App" button.
- "Open App" is disabled while isOpening or while any required input
  field is empty (validation derived from tool.inputSchema.required).
- No annotations, progress, or cancel — execution is delegated to the
  embedded app, not run as an MCP tool call from the panel.

Convention notes:
- Issue text references @tabler IconChevronRight / IconPlayerPlay; the
  v2 web client already uses react-icons (md/ri namespaces), so this PR
  uses MdChevronRight and MdPlayArrow for consistency rather than
  introducing a second icon library.

Stories: AppListItem (Default, Selected, WithIcon, NoDescription, LongName);
AppDetailPanel (NoFields, SimpleStringParam, MultipleParams, WithIcon,
Opening, ComplexSchema).

Tests: 22 cases covering rendering branches, callback wiring, and the
disabled-button derivation. Per-file coverage 100% across lines,
statements, functions, and branches for both new components.

Closes #1261

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

* fix(stories): inline SVG for WithIcon stories so they render reliably

The Wikipedia-hosted PNG used in the AppListItem and AppDetailPanel
WithIcon stories returned a broken image in Storybook (rate-limited /
hot-link blocked). Replace it with an inline SVG sun icon as a data
URI so the stories render offline, in Chromatic, and on any network.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

* test(apps): address PR #1273 review feedback

- Extract resolveDisplayLabel(name, title?) to src/utils/toolUtils.ts and
  migrate all four call sites (AppListItem, AppDetailPanel, ToolListItem,
  ToolDetailPanel) to consume it. Avoids the fourth copy when the next
  list/detail screen arrives. Includes a small unit suite.

- AppDetailPanel: only render the <Divider/> when the schema has at least
  one property — previously a no-input app showed an orphaned separator
  between the description and the Open App button.

- AppDetailPanel: align PanelTitle truncate to `true` (matches the
  ItemLabel form used in AppListItem / ToolListItem); behaviorally
  identical, just less surprising for future readers.

- AppDetailPanel: add an inline comment explaining that SchemaForm is
  disabled only while isOpening, not while validation fails — users
  should be able to keep filling required fields. The validation gate
  lives on the Open App button.

- Extract the inline SUN_ICON_SVG data URI used by the WithIcon stories
  to src/test/fixtures/storyIcons.ts so the next story that needs it
  doesn't grow a third copy.

- Tests: add the AppDetailPanel divider-conditional cases (rendered
  with fields, omitted without). Per-file coverage stays at 100% for
  AppListItem, AppDetailPanel, ToolListItem, ToolDetailPanel, and the
  new toolUtils. Suite: 70 files / 618 tests passing.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

* test(toolUtils): rename empty-string test for readability

Drops the doubled "is ... is preserved" phrase in the test name.
Behavior unchanged.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

clients/web/src/test/fixtures/storyIcons.ts

@@ -0,0 +1,7 @@
+/**
+ * Inline SVG data URIs used by Storybook stories that need a visible icon
+ * without depending on external network fetches (Chromatic, offline runs,
+ * play tests). Keep payloads small and self-contained.
+ */
+export const SUN_ICON_SVG =
+  "data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='gold'%3E%3Ccircle cx='12' cy='12' r='5'/%3E%3Cg stroke='gold' stroke-width='2' stroke-linecap='round'%3E%3Cline x1='12' y1='2' x2='12' y2='5'/%3E%3Cline x1='12' y1='19' x2='12' y2='22'/%3E%3Cline x1='2' y1='12' x2='5' y2='12'/%3E%3Cline x1='19' y1='12' x2='22' y2='12'/%3E%3Cline x1='4.93' y1='4.93' x2='7.05' y2='7.05'/%3E%3Cline x1='16.95' y1='16.95' x2='19.07' y2='19.07'/%3E%3Cline x1='4.93' y1='19.07' x2='7.05' y2='16.95'/%3E%3Cline x1='16.95' y1='7.05' x2='19.07' y2='4.93'/%3E%3C/g%3E%3C/svg%3E";