[refactor] Improve updates/notifications domain organization (#5590)

* [refactor] Move update-related functionality to platform/updates domain

Reorganizes release management, version compatibility, and notification functionality
following Domain-Driven Design principles, mirroring VSCode's architecture pattern.

- Move releaseService.ts to platform/updates/common/
- Move releaseStore.ts to platform/updates/common/
- Move versionCompatibilityStore.ts to platform/updates/common/
- Move useFrontendVersionMismatchWarning.ts to platform/updates/common/
- Move toastStore.ts to platform/updates/common/
- Move ReleaseNotificationToast.vue to platform/updates/components/
- Move WhatsNewPopup.vue to platform/updates/components/
- Update 25+ import paths across codebase and tests

This creates a cohesive "updates" domain containing all functionality related to
software updates, version checking, release notifications, and user communication
about application state changes.

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

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

* fix imports

---------

Co-authored-by: Claude <noreply@anthropic.com>

src/components/load3d/Load3D.vue

@@ -102,9 +102,9 @@ import {
   UpDirection
 } from '@/extensions/core/load3d/interfaces'
 import { useSettingStore } from '@/platform/settings/settingStore'
+import { useToastStore } from '@/platform/updates/common/toastStore'
 import type { CustomInputSpec } from '@/schemas/nodeDef/nodeDefSchemaV2'
 import type { ComponentWidget } from '@/scripts/domWidget'
-import { useToastStore } from '@/stores/toastStore'
 
 const { t } = useI18n()
 const { widget } = defineProps<{