Handle Chrome bookmarks API failures safely

[rudra-chothe]

Summary

• Fixed browser bookmark loading so Chrome bookmarks API failures are handled safely.
• Prevented the bookmarks section from getting stuck in loading when chrome.bookmarks is unavailable or rejects.
• Added fallback/error handling in the bookmark hook and surfaced a safe UI fallback state in the bookmarks section.

Closes #123

Type of Change

• Bug fix
• New feature
• Documentation update
• Refactor (no behavior change)
• Chore / tooling
• UI polish

Screenshots / Screen Recording

N/A

How to Test

1. Run npm run dev (or build/load extension as needed).
2. Open the dashboard and verify bookmarks load normally in a valid extension context.
3. Trigger a failing/unavailable chrome.bookmarks scenario (e.g., missing permission/unavailable runtime context).
4. Open the bookmarks section and confirm:
   • loading stops,
   • fallback/error state is shown,
   • dashboard remains usable.
5. Verify quality checks:
   • npm run lint
   • npm run typecheck
   • npm run build

Checklist

• I linked the related issue, if one exists.
• I assigned myself before opening the PR, if required.
• npm run lint passes.
• npm run typecheck passes.
• npm run build succeeds.
• I reviewed my own changes before requesting review.
• I did not change unrelated files.
• I updated documentation if needed.