refactor: simplify PackInstallButton isInstalling state management

- Remove isInstalling prop from PackInstallButton component
- Use internal computed property with comfyManagerStore.isPackInstalling()
- Remove redundant isInstalling computations from parent components
- Fix test mocks for useConflictDetection and es-toolkit/compat
- Clean up unused imports and inject dependencies

This centralizes the installation state management in the store,
reducing code duplication and complexity across components.

🤖 Generated with [Claude Code](https://claude.ai/code)

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

tests-ui/tests/components/dialog/footer/ManagerProgressFooter.test.ts

@@ -21,6 +21,12 @@ vi.mock('@/stores/dialogStore')
 vi.mock('@/stores/settingStore')
 vi.mock('@/stores/commandStore')
 vi.mock('@/services/comfyManagerService')
+vi.mock('@/composables/useConflictDetection', () => ({
+  useConflictDetection: vi.fn(() => ({
+    conflictedPackages: { value: [] },
+    performConflictDetection: vi.fn().mockResolvedValue(undefined)
+  }))
+}))
 
 // Mock useEventListener to capture the event handler
 let reconnectHandler: (() => void) | null = null