[refactor] Manager dialog simplification (#8041)

## Summary
Simplifies the Manager dialog by consolidating components and using
BaseModalLayout with v-model support for right panel state.

## Changes
- **Consolidation**: Merged ManagerDialogContent, ManagerHeader,
ManagerNavSidebar, RegistrySearchBar, and SearchFilterDropdown into
single ManagerDialog component
- **Right panel**: Added v-model:rightPanelOpen to BaseModalLayout for
external panel state control; clicking a node card now auto-opens the
info panel
- **Cleanup**: Removed unused useResponsiveCollapse composable, TabItem
and SearchOption types
- **UI tweaks**: Moved action buttons (Install All/Update All) from
header-right-area to contentFilter area


[manager-capture.webm](https://github.com/user-attachments/assets/2dd6092a-965d-4885-8ba6-6a2cc51f024a)

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

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-8041-refactor-Manager-dialog-simplification-2e86d73d3650815ba699e49a2748b682)
by [Unito](https://www.unito.io)

---------

Co-authored-by: GitHub Action <action@github.com>
Co-authored-by: github-actions <github-actions@github.com>

src/workbench/extensions/manager/composables/useManagerState.test.ts

@@ -53,6 +53,13 @@ vi.mock('@/stores/toastStore', () => ({
   }))
 }))
 
+vi.mock('@/workbench/extensions/manager/composables/useManagerDialog', () => ({
+  useManagerDialog: vi.fn(() => ({
+    show: vi.fn(),
+    hide: vi.fn()
+  }))
+}))
+
 describe('useManagerState', () => {
   beforeEach(() => {
     vi.clearAllMocks()