## Summary
- Add `WithAPIKey(key string)` option to `PrivilegeHandler`
- When set, `Fetch()` sends `Authorization: Bearer <key>` header
- Backward compatible: no key = no header (existing behavior)
## Test plan
- [x] Unit test verifying Authorization header is sent
- [x] Unit test verifying no header without key
- [x] Existing tests still pass
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Reviewed-on: #294
Adds multiple tests to verify the thread-safety of the
Fetch method and the handling of privileges in concurrent
operations. Tests include concurrent fetching, reading
privileges, and processing with multiple goroutines.
Ensures no errors occur during operations and verifies
privileges are set correctly.
Add support for the salary privilege in the privilege handler.
Implement associated logic to process and validate the
salary privilege in the test cases. Update the data
structures to include the new privilege and ensure
correct functionality in the privilege processing flow.
argoyle
