refactor: simplify job tabs

- Remove stargazers tab and related functionality
- Remove imports tab (merge with applicants)
- Remove import drawer and all import-related logic
- Remove import event handlers and helper functions
- Reorder tabs: matches first, applicants second
- Update default tab to matches
- Clean up assign_applicants function

The job view now has only two tabs: Matches and Applicants, with a much cleaner interface.

Author: zcesur