feat(auth): add view as user and role functionality for owners

Allow owners to impersonate users or roles for debugging permissions.
Add view-as targets to user sessions and resolve effective permissions.
Display a persistent banner in the app shell to exit view-as mode.

system-wordings.ts

@@ -78,6 +78,12 @@ export const systemWordingMessages = {
       logout: 'Log out',
       register: 'Register'
     },
+    viewAs: {
+      banner: 'View As {name}',
+      exit: 'Exit',
+      userAction: 'View As user',
+      roleAction: 'View As role'
+    },
     search: {
       label: 'Search Pokopia Wiki',
       placeholder: 'Search wiki',
@@ -1530,6 +1536,12 @@ export const systemWordingMessages = {
       logout: '退出',
       register: '注册'
     },
+    viewAs: {
+      banner: 'View As {name}',
+      exit: '退出',
+      userAction: '以用户身份 View As',
+      roleAction: '以角色身份 View As'
+    },
     search: {
       label: '搜索 Pokopia Wiki',
       placeholder: '搜索 Wiki',