[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/stores/conflictDetectionStore.ts

@@ -0,0 +1,70 @@
+import { defineStore } from 'pinia'
+import { computed, ref } from 'vue'
+
+import type { ConflictDetectionResult } from '@/types/conflictDetectionTypes'
+
+export const useConflictDetectionStore = defineStore(
+  'conflictDetection',
+  () => {
+    // State
+    const conflictedPackages = ref<ConflictDetectionResult[]>([])
+    const isDetecting = ref(false)
+    const lastDetectionTime = ref<string | null>(null)
+
+    // Getters
+    const hasConflicts = computed(() =>
+      conflictedPackages.value.some((pkg) => pkg.has_conflict)
+    )
+
+    const getConflictsForPackageByID = computed(
+      () => (packageId: string) =>
+        conflictedPackages.value.find((pkg) => pkg.package_id === packageId)
+    )
+
+    const bannedPackages = computed(() =>
+      conflictedPackages.value.filter((pkg) =>
+        pkg.conflicts.some((conflict) => conflict.type === 'banned')
+      )
+    )
+
+    const securityPendingPackages = computed(() =>
+      conflictedPackages.value.filter((pkg) =>
+        pkg.conflicts.some((conflict) => conflict.type === 'pending')
+      )
+    )
+
+    // Actions
+    function setConflictedPackages(packages: ConflictDetectionResult[]) {
+      conflictedPackages.value = [...packages]
+    }
+
+    function clearConflicts() {
+      conflictedPackages.value = []
+    }
+
+    function setDetecting(detecting: boolean) {
+      isDetecting.value = detecting
+    }
+
+    function setLastDetectionTime(time: string) {
+      lastDetectionTime.value = time
+    }
+
+    return {
+      // State
+      conflictedPackages,
+      isDetecting,
+      lastDetectionTime,
+      // Getters
+      hasConflicts,
+      getConflictsForPackageByID,
+      bannedPackages,
+      securityPendingPackages,
+      // Actions
+      setConflictedPackages,
+      clearConflicts,
+      setDetecting,
+      setLastDetectionTime
+    }
+  }
+)