[refactor] Migrate minimap to domain-driven renderer architecture (#5069)

* move ref initialization to the component

* remove redundant init

* [refactor] Move minimap to domain-driven renderer structure

- Create new src/renderer/extensions/minimap/ structure following domain-driven design
- Add composables: useMinimapGraph, useMinimapViewport, useMinimapRenderer, useMinimapInteraction, useMinimapSettings
- Add minimapCanvasRenderer with efficient batched rendering
- Add comprehensive type definitions in types.ts
- Remove old src/composables/useMinimap.ts composable
- Implement proper separation of concerns with dedicated composables for each domain

The new structure provides cleaner APIs, better performance through batched rendering,
and improved maintainability through domain separation.

* [test] Fix minimap tests for new renderer structure

- Update all test imports to use new renderer paths
- Fix mock implementations to match new composable APIs
- Add proper RAF mocking for throttled functions
- Fix type assertions to handle strict TypeScript checks
- Update test expectations for new implementation behavior
- Fix viewport transform calculations in tests
- Handle async/throttled behavior correctly in tests

All 28 minimap tests now passing with new architecture.

* [fix] Remove unused init import in MiniMap component

* [refactor] Move useWorkflowThumbnail to renderer/thumbnail structure

- Moved useWorkflowThumbnail from src/composables to src/renderer/thumbnail/composables
- Updated all imports in components, stores and services
- Moved test file to match new structure
- This ensures all rendering-related composables live in the renderer directory

* [test] Fix minimap canvas renderer test for connections

- Fixed mock setup for graph links to match LiteGraph's hybrid Map/Object structure
- LiteGraph expects links to be accessible both as a Map and as an object
- Test now properly verifies connection rendering functionality

src/components/topbar/WorkflowTab.vue

@@ -40,7 +40,7 @@ import {
   usePragmaticDraggable,
   usePragmaticDroppable
 } from '@/composables/usePragmaticDragAndDrop'
-import { useWorkflowThumbnail } from '@/composables/useWorkflowThumbnail'
+import { useWorkflowThumbnail } from '@/renderer/thumbnail/composables/useWorkflowThumbnail'
 import { useWorkflowService } from '@/services/workflowService'
 import { useSettingStore } from '@/stores/settingStore'
 import { ComfyWorkflow } from '@/stores/workflowStore'