fix(namespace): relocate delete i18n keys to match frontend usage

The delete translations lived under myNamespaces.delete.* but every caller
looks them up as namespace.delete.* (my-namespaces.tsx and
delete-namespace-dialog.tsx). i18next fell back to the raw key, so the
rendered button read 'namespace.delete.button' and the E2E regex
/^delete$/i never matched. Move the block under namespace.* in both
locales to make the keys resolvable.

web/src/i18n/locales/en.json

@@ -428,24 +428,6 @@
     "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.",
@@ -770,7 +752,25 @@
     "notFound": "Namespace not found",
     "skillList": "Skills",
     "emptyTitle": "No skills",
-    "emptyDescription": "No skills have been published in this namespace yet"
+    "emptyDescription": "No skills have been published in this namespace yet",
+    "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"
+      }
+    }
   },
   "skillDetail": {
     "back": "Back",

web/src/i18n/locales/zh.json

@@ -428,24 +428,6 @@
     "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。",
@@ -770,7 +752,25 @@
     "notFound": "命名空间不存在",
     "skillList": "技能列表",
     "emptyTitle": "暂无技能",
-    "emptyDescription": "该命名空间下还没有发布任何技能"
+    "emptyDescription": "该命名空间下还没有发布任何技能",
+    "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"
+      }
+    }
   },
   "skillDetail": {
     "back": "返回上一页",