fix: resolve bugs in benchmark lifecycle, snapshot filtering, and dark mode

- Fix PVC bind loop leak on unmount via cancellation ref
- Fix DeleteOptions body structure for proper foreground propagation
- Filter snapshots to tns-csi driver only (was showing all drivers)
- Fix stale closures in Escape key handlers with useCallback
- Add loading state to cleanup delete button, remove window.confirm/alert
- Use CSS custom properties for protocol chart colors (dark mode support)
- Fix all 35 ESLint warnings (import sort, indent, boolean attrs)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/test-helpers.tsx

@@ -4,7 +4,6 @@
  */
 
 import { vi } from 'vitest';
-import type { TnsCsiContextValue } from './api/TnsCsiDataContext';
 import type {
   CSIDriver,
   TnsCsiPersistentVolume,
@@ -15,6 +14,7 @@ import type {
   VolumeSnapshotClass,
 } from './api/k8s';
 import type { TnsCsiMetrics } from './api/metrics';
+import type { TnsCsiContextValue } from './api/TnsCsiDataContext';
 
 // ---------------------------------------------------------------------------
 // Default context value (everything empty / zeroed)