fix(auth): recover login page from stale lazy-loaded chunks after logout

[zhukai9527]

Summary

• Added a client-side recovery helper for stale dynamic import failures in web/src/shared/lib/dynamic-import-recovery.ts.
• Updated the lazy route loader in web/src/app/router.tsx to detect login-page chunk fetch failures, trigger a one-time full page reload, and clear the reload guard after
  the router resolves normally.
• This is needed because after logout, the app navigates to the lazily loaded /login route. If the browser is still running an older entry chunk while the server has already deployed a new asset hash, the login chunk request can
  fail until the page is refreshed manually.

Validation

• Backend tests passed
• Frontend typecheck/build passed
• OpenAPI SDK regenerated or checked when API contracts changed
• Smoke test run when relevant

Commands run:

git diff -- web/src/app/router.tsx web/src/shared/lib/dynamic-import-recovery.ts
git checkout -b fix-login-chunk-recovery
git add -- web/src/app/router.tsx web/src/shared/lib/dynamic-import-recovery.ts
git diff --cached -- web/src/app/router.tsx web/src/shared/lib/dynamic-import-recovery.ts
git commit -m "fix(auth): recover from stale login chunks after logout"
git push -u origin fix-login-chunk-recovery
cmd /c pnpm typecheck
cmd /c pnpm test -- src/shared/lib/dynamic-import-recovery.test.ts

## Risk

- User-facing impact: Logout-to-login transitions should self-recover from stale asset hash mismatches instead of showing Failed to fetch dynamically imported module.
- Deployment or migration impact: No backend, schema, or migration impact. Frontend-only runtime behavior change.
- Rollback approach: Revert this commit or redeploy the previous frontend bundle.

## Notes

- Related issue: Logout followed by navigation to /login can fail on deployed environments when lazy-loaded login chunks are stale.
- Follow-up work: Consider tightening static asset and index.html cache strategy at the Nginx/CDN layer to reduce stale entrypoint vs chunk mismatches.
- Docs or operator runbooks updated when behavior changed: No

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