fix: remove any types, dead code, unused exports; add comprehensive tests

- Fix handleRotate bug ignoring Result from rotateSealedSecret()
- Fix dead code branch in useControllerHealth
- Replace all `any` types with `unknown` + type guards
- Delete unused functions/exports (452 lines removed)
- Add 18 new test files covering all hooks, libs, and components
- 233 tests passing, zero tsc errors, zero lint issues

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

src/components/LoadingSkeletons.test.tsx

@@ -0,0 +1,47 @@
+/**
+ * Unit tests for LoadingSkeletons components
+ */
+
+import { render } from '@testing-library/react';
+import React from 'react';
+import { describe, expect, it } from 'vitest';
+import {
+  ControllerHealthSkeleton,
+  SealedSecretDetailSkeleton,
+  SealedSecretListSkeleton,
+  SealingKeysListSkeleton,
+} from './LoadingSkeletons';
+
+describe('LoadingSkeletons', () => {
+  it('should render SealedSecretListSkeleton without errors', () => {
+    const { container } = render(<SealedSecretListSkeleton />);
+    expect(container.querySelector('.MuiSkeleton-root')).toBeTruthy();
+  });
+
+  it('should render SealedSecretDetailSkeleton without errors', () => {
+    const { container } = render(<SealedSecretDetailSkeleton />);
+    expect(container.querySelector('.MuiSkeleton-root')).toBeTruthy();
+  });
+
+  it('should render SealingKeysListSkeleton without errors', () => {
+    const { container } = render(<SealingKeysListSkeleton />);
+    expect(container.querySelector('.MuiSkeleton-root')).toBeTruthy();
+  });
+
+  it('should render ControllerHealthSkeleton without errors', () => {
+    const { container } = render(<ControllerHealthSkeleton />);
+    expect(container.querySelector('.MuiSkeleton-root')).toBeTruthy();
+  });
+
+  it('should render list skeleton with multiple rows', () => {
+    const { container } = render(<SealedSecretListSkeleton />);
+    const skeletons = container.querySelectorAll('.MuiSkeleton-root');
+    expect(skeletons.length).toBe(5);
+  });
+
+  it('should render detail skeleton with multiple sections', () => {
+    const { container } = render(<SealedSecretDetailSkeleton />);
+    const skeletons = container.querySelectorAll('.MuiSkeleton-root');
+    expect(skeletons.length).toBeGreaterThanOrEqual(3);
+  });
+});