feat(namespace): implement frontend delete functionality with reason input

Add complete frontend implementation for namespace deletion:
- API layer: add delete() method to namespaceApi
- Hooks layer: add useDeleteNamespace() mutation hook
- UI layer: add DeleteNamespaceDialog component with reason input
- Add delete button in my-namespaces page (only shown when canDelete is true)
- Add i18n keys for delete confirmation, reason input, and success/error messages
- Update ManagedNamespace type to include canDelete permission flag
- Fix test mocks to include canDelete property

The delete dialog requires users to provide a deletion reason before confirming,
following the backend requirement. After successful deletion, users are redirected
to the my-namespaces page.

web/src/api/client.ts

@@ -732,6 +732,16 @@ export const namespaceApi = {
       headers: await ensureCsrfHeaders(),
     })
   },
+
+  async delete(slug: string, reason: string): Promise<void> {
+    await fetchJson<void>(`${WEB_API_PREFIX}/namespaces/${normalizeNamespaceSlug(slug)}`, {
+      method: 'DELETE',
+      headers: await ensureCsrfHeaders({
+        'Content-Type': 'application/json',
+      }),
+      body: JSON.stringify({ reason: reason.trim() }),
+    })
+  },
 }
 
 export const tokenApi = {

web/src/api/types.ts

@@ -121,6 +121,7 @@ export interface ManagedNamespace extends Namespace {
   canUnfreeze: boolean
   canArchive: boolean
   canRestore: boolean
+  canDelete: boolean
 }
 
 export interface NamespaceMember {

web/src/features/namespace/delete-namespace-dialog.tsx

@@ -0,0 +1,97 @@
+import { useState } from 'react'
+import { useTranslation } from 'react-i18next'
+import {
+  Dialog,
+  DialogContent,
+  DialogDescription,
+  DialogFooter,
+  DialogHeader,
+  DialogTitle,
+} from '@/shared/ui/dialog'
+import { Button } from '@/shared/ui/button'
+import { Textarea } from '@/shared/ui/textarea'
+import { Label } from '@/shared/ui/label'
+
+interface DeleteNamespaceDialogProps {
+  open: boolean
+  onOpenChange: (open: boolean) => void
+  namespaceName: string
+  onConfirm: (reason: string) => void | Promise<void>
+}
+
+export function DeleteNamespaceDialog({
+  open,
+  onOpenChange,
+  namespaceName,
+  onConfirm,
+}: DeleteNamespaceDialogProps) {
+  const { t } = useTranslation()
+  const [reason, setReason] = useState('')
+  const [isSubmitting, setIsSubmitting] = useState(false)
+
+  const handleConfirm = async () => {
+    if (!reason.trim()) {
+      return
+    }
+
+    setIsSubmitting(true)
+    try {
+      await onConfirm(reason)
+      setReason('')
+      onOpenChange(false)
+    } finally {
+      setIsSubmitting(false)
+    }
+  }
+
+  const handleOpenChange = (newOpen: boolean) => {
+    if (!isSubmitting) {
+      if (!newOpen) {
+        setReason('')
+      }
+      onOpenChange(newOpen)
+    }
+  }
+
+  return (
+    <Dialog open={open} onOpenChange={handleOpenChange}>
+      <DialogContent>
+        <DialogHeader>
+          <DialogTitle>{t('namespace.delete.confirm.title')}</DialogTitle>
+          <DialogDescription>
+            {t('namespace.delete.confirm.description', { name: namespaceName })}
+          </DialogDescription>
+        </DialogHeader>
+        <div className="space-y-4 py-4">
+          <div className="space-y-2">
+            <Label htmlFor="delete-reason">{t('namespace.delete.reason.label')}</Label>
+            <Textarea
+              id="delete-reason"
+              placeholder={t('namespace.delete.reason.placeholder')}
+              value={reason}
+              onChange={(e) => setReason(e.target.value)}
+              disabled={isSubmitting}
+              rows={3}
+            />
+          </div>
+        </div>
+        <DialogFooter className="sm:justify-center sm:space-x-3">
+          <Button
+            variant="outline"
+            onClick={() => handleOpenChange(false)}
+            disabled={isSubmitting}
+          >
+            {t('dialog.cancel')}
+          </Button>
+          <Button
+            variant="destructive"
+            onClick={handleConfirm}
+            disabled={!reason.trim() || isSubmitting}
+          >
+            {t('namespace.delete.button')}
+          </Button>
+        </DialogFooter>
+      </DialogContent>
+    </Dialog>
+  )
+}

web/src/features/review/review-paths.test.ts

@@ -45,6 +45,7 @@ describe('review-paths', () => {
         canUnfreeze: false,
         canArchive: false,
         canRestore: false,
+        canDelete: false,
         currentUserRole: 'ADMIN',
         createdAt: '',
       },
@@ -59,6 +60,7 @@ describe('review-paths', () => {
         canUnfreeze: false,
         canArchive: false,
         canRestore: false,
+        canDelete: false,
         currentUserRole: 'OWNER',
         createdAt: '',
       },
@@ -78,6 +80,7 @@ describe('review-paths', () => {
         canUnfreeze: false,
         canArchive: false,
         canRestore: false,
+        canDelete: false,
         currentUserRole: 'MEMBER',
         createdAt: '',
       },
@@ -98,6 +101,7 @@ describe('review-paths', () => {
         canUnfreeze: false,
         canArchive: false,
         canRestore: false,
+        canDelete: false,
         currentUserRole: 'ADMIN',
         createdAt: '',
       },

web/src/i18n/locales/en.json

@@ -428,6 +428,24 @@
     "unfreeze": "Unfreeze",
     "archive": "Archive",
     "restore": "Restore",
+    "delete": {
+      "button": "Delete",
+      "confirm": {
+        "title": "Delete namespace",
+        "description": "\"{{name}}\" will be permanently deleted. This action cannot be undone. Please provide a reason for deletion."
+      },
+      "reason": {
+        "label": "Deletion reason",
+        "placeholder": "Please explain why this namespace needs to be deleted..."
+      },
+      "success": {
+        "title": "Namespace deleted",
+        "description": "\"{{name}}\" has been permanently deleted."
+      },
+      "error": {
+        "title": "Failed to delete namespace"
+      }
+    },
     "activeHint": "This namespace is fully active and can continue managing members, reviews, and skill publishing.",
     "frozenHint": "This namespace is frozen. Members can still view it, but it is read-only and cannot publish or change membership.",
     "archivedHint": "This namespace is archived. Public entry points are hidden, but you can still view and restore it from the dashboard.",

web/src/i18n/locales/zh.json

@@ -428,6 +428,24 @@
     "unfreeze": "解冻",
     "archive": "归档",
     "restore": "恢复",
+    "delete": {
+      "button": "删除",
+      "confirm": {
+        "title": "删除命名空间",
+        "description": "\"{{name}}\"将被永久删除，此操作无法撤销。请提供删除原因。"
+      },
+      "reason": {
+        "label": "删除原因",
+        "placeholder": "请说明为什么需要删除此命名空间..."
+      },
+      "success": {
+        "title": "命名空间已删除",
+        "description": "\"{{name}}\"已被永久删除。"
+      },
+      "error": {
+        "title": "删除命名空间失败"
+      }
+    },
     "activeHint": "命名空间运行正常，可继续管理成员、处理审核和发布技能。",
     "frozenHint": "命名空间已冻结。成员仍可查看，但当前处于只读状态，不能继续发布或变更成员。",
     "archivedHint": "命名空间已归档。公开入口已隐藏，但你仍可在管理台查看并恢复。",

web/src/pages/dashboard/my-namespaces.tsx

@@ -9,8 +9,9 @@ import { EmptyState } from '@/shared/components/empty-state'
 import { ConfirmDialog } from '@/shared/components/confirm-dialog'
 import { DashboardPageHeader } from '@/shared/components/dashboard-page-header'
 import { CreateNamespaceDialog } from '@/features/namespace/create-namespace-dialog'
-import { useArchiveNamespace, useFreezeNamespace, useMyNamespaces, useRestoreNamespace, useUnfreezeNamespace } from '@/shared/hooks/use-namespace-queries'
+import { useArchiveNamespace, useDeleteNamespace, useFreezeNamespace, useMyNamespaces, useRestoreNamespace, useUnfreezeNamespace } from '@/shared/hooks/use-namespace-queries'
 import { toast } from '@/shared/lib/toast'
+import { DeleteNamespaceDialog } from '@/features/namespace/delete-namespace-dialog'
 
 type PendingNamespaceAction =
   | { action: 'freeze'; slug: string; name: string }
@@ -18,6 +19,11 @@ type PendingNamespaceAction =
   | { action: 'archive'; slug: string; name: string }
   | { action: 'restore'; slug: string; name: string }
 
+type PendingDeleteAction = {
+  slug: string
+  name: string
+}
+
 /**
  * Dashboard page for namespaces the current user can manage or review. It owns
  * namespace lifecycle actions because each action combines permissions, copy,
@@ -29,11 +35,13 @@ export function MyNamespacesPage() {
   const { hasRole } = useAuth()
   const canCreateNamespace = hasRole('SKILL_ADMIN') || hasRole('SUPER_ADMIN')
   const [pendingAction, setPendingAction] = useState<PendingNamespaceAction | null>(null)
+  const [pendingDelete, setPendingDelete] = useState<PendingDeleteAction | null>(null)
   const { data: namespaces, isLoading } = useMyNamespaces()
   const freezeMutation = useFreezeNamespace()
   const unfreezeMutation = useUnfreezeNamespace()
   const archiveMutation = useArchiveNamespace()
   const restoreMutation = useRestoreNamespace()
+  const deleteMutation = useDeleteNamespace()
 
   const handleNamespaceClick = (slug: string) => {
     navigate({ to: `/space/${encodeURIComponent(slug)}` })
@@ -157,6 +165,28 @@ export function MyNamespacesPage() {
     }
   }
 
+  const handleDeleteNamespace = async (reason: string) => {
+    if (!pendingDelete) {
+      return
+    }
+
+    try {
+      await deleteMutation.mutateAsync({ slug: pendingDelete.slug, reason })
+      toast.success(
+        t('namespace.delete.success.title'),
+        t('namespace.delete.success.description', { name: pendingDelete.name }),
+      )
+      setPendingDelete(null)
+      navigate({ to: '/dashboard/namespaces' })
+    } catch (error) {
+      toast.error(
+        t('namespace.delete.error.title'),
+        error instanceof Error ? error.message : '',
+      )
+      throw error
+    }
+  }
+
   if (isLoading) {
     return (
       <div className="space-y-4 animate-fade-up">
@@ -281,6 +311,18 @@ export function MyNamespacesPage() {
                       {t('myNamespaces.restore')}
                     </Button>
                   )}
+                  {namespace.canDelete && (
+                    <Button
+                      variant="destructive"
+                      size="sm"
+                      onClick={(e) => {
+                        e.stopPropagation()
+                        setPendingDelete({ slug: namespace.slug, name: namespace.displayName })
+                      }}
+                    >
+                      {t('namespace.delete.button')}
+                    </Button>
+                  )}
                 </div>
               </div>
             </Card>
@@ -311,6 +353,17 @@ export function MyNamespacesPage() {
         variant={pendingAction ? resolveActionCopy(pendingAction.action, pendingAction.name).variant : 'default'}
         onConfirm={handleNamespaceAction}
       />
+
+      <DeleteNamespaceDialog
+        open={!!pendingDelete}
+        onOpenChange={(open) => {
+          if (!open) {
+            setPendingDelete(null)
+          }
+        }}
+        namespaceName={pendingDelete?.name ?? ''}
+        onConfirm={handleDeleteNamespace}
+      />
     </div>
   )
 }

web/src/shared/hooks/use-namespace-queries.ts

@@ -186,3 +186,14 @@ export function useRestoreNamespace() {
     },
   })
 }
+
+export function useDeleteNamespace() {
+  const queryClient = useQueryClient()
+
+  return useMutation({
+    mutationFn: ({ slug, reason }: { slug: string; reason: string }) => namespaceApi.delete(slug, reason),
+    onSuccess: (_data, variables) => {
+      invalidateNamespaceQueries(queryClient, variables.slug)
+    },
+  })
+}