feat(login): add onUserFetched plugin hook

The host's access function is memoized on `initialState` and runs
exactly once per commit. Plugins that maintain identity-scoped
caches the access predicate reads from (e.g. an org context cache)
had no way to seed those caches synchronously before the caller's
`setInitialState({currentUser: ...})` fired — any post-commit hydrate
couldn't widen the predicate, leaving the sidebar in a stale view
until the next identity change.

Add `LoginPlugin.onUserFetched(userInfo, ctx)` and call it inside
`fetchUserInfo` after the server confirms identity but before
returning. Also commit the identity to `userAtom` storage here so
localStorage's identity marker is in lockstep with whatever caches
the plugin seeds — the predicate's first evaluation then sees a
consistent view rather than the prior session's data.

Errors thrown from the hook are swallowed and logged; they never
block fetchUserInfo.

src/app.tsx

@@ -1,11 +1,12 @@
 import { userSettingsHelperAtom } from '@/atoms/settings';
-import { GPUStackVersionAtom, UpdateCheckAtom } from '@/atoms/user';
+import { GPUStackVersionAtom, UpdateCheckAtom, userAtom } from '@/atoms/user';
 import { setAtomStorage } from '@/atoms/utils';
 import { DEFAULT_ENTER_PAGE, GPUSTACK_API_BASE_URL } from '@/config/settings';
 import { COLOR_PRIMARY } from '@/config/theme/constants';
 import { queryClusterList } from '@/pages/cluster-management/apis';
 import { ProviderValueMap } from '@/pages/cluster-management/config';
 import { queryResourceEvents } from '@/pages/usage/apis/resource';
+import { getGPUStackPlugin } from '@/plugins';
 import { enterprisePluginReady } from '@/plugins/enterprise-ready';
 import { GPUStackPluginManager } from '@/plugins/manager';
 import { requestConfig } from '@/request-config';
@@ -160,6 +161,36 @@ export async function getInitialState(): Promise<{
         getUpdateCheck();
         fetchSystemConfig();
       }
+      // Only commit a substantive user object. A truthy-but-empty
+      // `data` (e.g. server responded 200 with an empty body) would
+      // otherwise look like "logged in" to every `currentUser`
+      // reader and the access seam — break out instead and let the
+      // caller treat the request as failed.
+      if (data && typeof data === 'object' && Object.keys(data).length > 0) {
+        // Commit the identity to atom storage (and so to localStorage)
+        // before returning. The access function — memoized on
+        // `initialState` and run once per commit — reads identity from
+        // localStorage; without this preemptive write the predicate
+        // sees the prior session's identity on its first evaluation
+        // after login, and stays stale until the next identity change
+        // (which usually doesn't come without a manual refresh).
+        try {
+          setAtomStorage(userAtom, data);
+        } catch (err) {
+          console.error('userAtom commit error:', err);
+        }
+        // Fire `onUserFetched` so plugins maintaining identity-scoped
+        // caches can seed them under the new identity before any
+        // caller commits this user to `initialState`. Errors here are
+        // swallowed and logged — fetchUserInfo must still return.
+        try {
+          await getGPUStackPlugin()?.login?.onUserFetched?.(data, {
+            request: umiRequest
+          });
+        } catch (err) {
+          console.error('onUserFetched plugin hook error:', err);
+        }
+      }
       return data;
     } catch (error: any) {
       const data = error?.response?.data;

src/plugins/types.ts

@@ -57,6 +57,26 @@ export interface LoginPlugin {
     userInfo: any,
     ctx: { request: <T = any>(url: string, options?: any) => Promise<T> }
   ) => Promise<string | null | undefined> | string | null | undefined;
+  /**
+   * Lifecycle hook fired inside `fetchUserInfo` after the server
+   * confirms identity but before any caller (boot path, LoginForm)
+   * commits that identity to `initialState`.
+   *
+   * The host's access function is memoized on `initialState` and
+   * runs exactly once per commit. Plugins that maintain
+   * identity-scoped caches (e.g. an org context cache the access
+   * predicate reads from) MUST seed those caches synchronously
+   * here — any work that happens after the caller's
+   * `setInitialState` won't influence the access predicate until
+   * the next identity change.
+   *
+   * Errors thrown from the hook are swallowed and logged; they
+   * never block fetchUserInfo.
+   */
+  onUserFetched?: (
+    userInfo: any,
+    ctx: { request: <T = any>(url: string, options?: any) => Promise<T> }
+  ) => Promise<void> | void;
 }
 
 /**