fix: resolve TypeScript compilation errors and failing tests

- Update registerDetailsViewSection and registerAppBarAction calls to match new Headlamp plugin API (single argument)
- Add SimpleTable mock to DashboardView tests
- Fix all TypeScript compilation errors
- All 50 tests now passing

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Co-Authored-By: Claude <noreply@anthropic.com>
Co-Authored-By: Happy <yesreply@happy.engineering>

src/components/NamespacesListView.tsx

@@ -118,7 +118,11 @@ function NamespaceDetailPanel({ namespace, onClose }: NamespaceDetailPanelProps)
           alignItems: 'center',
         }}
       >
-        <h2 style={{ margin: 0, color: 'var(--mui-palette-text-primary, var(--text-primary, #000))' }}>Polaris — {namespace}</h2>
+        <h2
+          style={{ margin: 0, color: 'var(--mui-palette-text-primary, var(--text-primary, #000))' }}
+        >
+          Polaris — {namespace}
+        </h2>
         <button
           onClick={onClose}
           style={{