test(dashboard): add unit tests for dynamic form components

- Create comprehensive test suite for DynamicField (21 tests)
- Create comprehensive test suite for DynamicConfigForm (10 tests)
- Create comprehensive test suite for FieldHookRegistry (21 tests)
- Configure Vitest 4.0.18 with jsdom environment
- Add test setup with ResizeObserver and matchMedia polyfills
- 52 tests total covering all core functionality

dashboard/src/test/setup.ts

@@ -0,0 +1,22 @@
+import '@testing-library/jest-dom/vitest'
+
+global.ResizeObserver = class ResizeObserver {
+  observe() {}
+  unobserve() {}
+  disconnect() {}
+}
+
+Object.defineProperty(window, 'matchMedia', {
+  writable: true,
+  value: (query: string) => ({
+    matches: false,
+    media: query,
+    onchange: null,
+    addListener: () => {},
+    removeListener: () => {},
+    addEventListener: () => {},
+    removeEventListener: () => {},
+    dispatchEvent: () => {},
+  }),
+})
+