[refactor] Migrate manager code from src/composables to src/workbench/extensions/manager (2/2) (#5722)

## Summary

Continuation of

- https://github.com/Comfy-Org/ComfyUI_frontend/pull/5662

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-5722-refactor-Migrate-manager-code-from-src-composables-to-src-workbench-extensions-manag-2766d73d36508165a4f5e1940967248f)
by [Unito](https://www.unito.io)

---------

Co-authored-by: Alexander Brown <drjkl@comfy.org>

src/workbench/extensions/manager/composables/useImportFailedDetection.ts

@@ -0,0 +1,85 @@
+import { type ComputedRef, computed, unref } from 'vue'
+import { useI18n } from 'vue-i18n'
+
+import { useDialogService } from '@/services/dialogService'
+import type { ConflictDetail } from '@/types/conflictDetectionTypes'
+import { useComfyManagerStore } from '@/workbench/extensions/manager/stores/comfyManagerStore'
+import { useConflictDetectionStore } from '@/workbench/extensions/manager/stores/conflictDetectionStore'
+
+/**
+ * Extracting import failed conflicts from conflict list
+ */
+function extractImportFailedConflicts(conflicts?: ConflictDetail[] | null) {
+  if (!conflicts) return null
+
+  const importFailedConflicts = conflicts.filter(
+    (item): item is ConflictDetail => item.type === 'import_failed'
+  )
+
+  return importFailedConflicts.length > 0 ? importFailedConflicts : null
+}
+
+/**
+ * Creating import failed dialog
+ */
+function createImportFailedDialog() {
+  const { t } = useI18n()
+  const { showErrorDialog } = useDialogService()
+
+  return (importFailedInfo: ConflictDetail[] | null) => {
+    if (importFailedInfo) {
+      const errorMessage =
+        importFailedInfo
+          .map((conflict) => conflict.required_value)
+          .filter(Boolean)
+          .join('\n') || t('manager.importFailedGenericError')
+
+      const error = new Error(errorMessage)
+
+      showErrorDialog(error, {
+        title: t('manager.failedToInstall'),
+        reportType: 'importFailedError'
+      })
+    }
+  }
+}
+
+/**
+ * Composable for detecting and handling import failed conflicts
+ * @param packageId - Package ID string or computed ref
+ * @returns Object with import failed detection and dialog handler
+ */
+export function useImportFailedDetection(
+  packageId?: string | ComputedRef<string> | null
+) {
+  const { isPackInstalled } = useComfyManagerStore()
+  const { getConflictsForPackageByID } = useConflictDetectionStore()
+
+  const isInstalled = computed(() =>
+    packageId ? isPackInstalled(unref(packageId)) : false
+  )
+
+  const conflicts = computed(() => {
+    const currentPackageId = unref(packageId)
+    if (!currentPackageId || !isInstalled.value) return null
+    return getConflictsForPackageByID(currentPackageId) || null
+  })
+
+  const importFailedInfo = computed(() => {
+    return extractImportFailedConflicts(conflicts.value?.conflicts)
+  })
+
+  const importFailed = computed(() => {
+    return importFailedInfo.value !== null
+  })
+
+  const showImportFailedDialog = createImportFailedDialog()
+
+  return {
+    importFailedInfo,
+    importFailed,
+    showImportFailedDialog: () =>
+      showImportFailedDialog(importFailedInfo.value),
+    isInstalled
+  }
+}