feat: resolve Zustand persist hydration causing redirect/layout flicker

[dataCenter430]

Related Issue

Persisted auth may hydrate after the first render, causing temporary redirects or flicker.

Closes #1260

Description

1. src/hooks/useAuthHydration.ts (new)

• Hook that returns true only after the auth store’s persist middleware has finished rehydrating.
• Uses useAuthStore.persist.hasHydrated() and onFinishHydration() so we don’t read token / initState / isFirstLaunch before they’re restored from storage.

2. src/routers/index.tsx

• ProtectedRoute uses useAuthHydration().
• Shows the loading spinner until hasHydrated is true, then runs the existing proxy check and INITIALIZE with the real token.
• Prevents briefly sending logged-in users to /login before hydration completes.

3. src/components/Layout/index.tsx

• Layout uses useAuthHydration().
• Keeps showing “Loading…” until the auth store has hydrated, then reads initState and isFirstLaunch.
• Prevents the install/onboarding screen from flashing before switching to the correct main content.

Why it’s better

• No auth flicker: Route guard and layout only use auth state after rehydration, so we don’t redirect to login or show wrong UI and then correct it.
• Single source of truth: Hydration is handled in one hook (useAuthHydration) and reused wherever auth-dependent UI is rendered.
• Uses Zustand’s API: Relies on persist.hasHydrated() and onFinishHydration() instead of ad-hoc timing or timeouts.
• Same loading UX: We still show a spinner/“Loading…” until we know the real auth state; we only avoid the incorrect redirect and layout flicker that happened when acting on unhydrated state.

What is the purpose of this pull request?

• Bug fix
• New Feature
• Documentation update
• Other

Contribution Guidelines Acknowledgement

• I have read and agree to the Eigent Contribution Guideline