Add comprehensive .github/copilot-instructions.md for coding agent onboarding (#43)

* Initial plan

* Add comprehensive .github/copilot-instructions.md

Co-authored-by: Mikefly123 <[email protected]>

* updtd

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Co-authored-by: copilot-swe-agent[bot] <[email protected]>
Co-authored-by: Mikefly123 <[email protected]>
Co-authored-by: ineskhou <[email protected]>

Author: 3 people