refactor: merge auto-fix into license-check workflow

Combines both workflows into one with two jobs:
1. license-check: Checks licenses, fails if needed, sets outputs
2. auto-create-fix-pr: Creates child PR if needed (only for non-forks)

Benefits:
- Single workflow file, easier to maintain
- Check fails (blocks merge) while still creating helpful fix PR
- Fork detection in first job, second job skips for forks
- Hash-based tracking prevents duplicate PRs

Author: SamMorrowDrums