feat(dashboard): sync Learning Space tabs with URL params and add Suspense boundaries

[GenerQAQ]

Why we need this PR?

Learning Space detail page tabs (metadata/skills/sessions) are not reflected in the URL, so users can't bookmark or share links to a specific tab. Also, several client components using useSearchParams lack <Suspense> boundaries, which triggers Next.js SSR warnings.

Describe your solution

1. Tab URL sync: Replace useState for activeTab with useSearchParams/usePathname so the active tab is read from ?tab= and updated via router.replace. Default tab is skills (no param needed).
2. Suspense boundaries: Wrap all client components using useSearchParams with <Suspense> to follow Next.js App Router requirements.

Implementation Tasks

• Sync Learning Space detail tab state with ?tab= URL search param
• Add <Suspense> to project/[id]/session/page.tsx
• Add <Suspense> to project/[id]/session/[sessionId]/task/page.tsx
• Add <Suspense> to project/[id]/learning-spaces/page.tsx
• Add <Suspense> to project/[id]/learning-spaces/[spaceId]/page.tsx
• Add <Suspense> to project/[id]/disk/page.tsx
• Add <Suspense> to new/[id]/page.tsx
• Add <Suspense> to new/page.tsx (extracted inner component)
• Add <Suspense> to auth/layout.tsx (wraps login page children)

Impact Areas

• Dashboard
• Client SDK (Python)
• Client SDK (TypeScript)
• Core Service
• API Server
• CLI Tool
• Documentation

Checklist

• Open your pull request against the dev branch.
• All tests pass in available continuous integration systems (e.g., GitHub Actions).
• Tests are added or modified as needed to cover code changes.