Added comprehensive feature discovery section to copilot-instructions.md:
- Quick Reference Table: 9 common scenarios with existing features
- Quick Search Commands: bash commands for feature discovery
- Feature Discovery by Category: 6 categories with 30+ features
- Decision Flowchart: 5-step verification process
- Historical Examples: why each feature was built
This helps users/AI agents discover existing features before rebuilding.
Co-authored-by: mindesbunister <32161838+mindesbunister@users.noreply.github.com>