Add experimental copilot-sdk engine with port-based LLM gateway support (#15642)

* Initial plan

* Add copilot-sdk engine implementation

Co-authored-by: pelikhan <4175913+pelikhan@users.noreply.github.com>

* Add tests for copilot-sdk engine and update existing tests

Co-authored-by: pelikhan <4175913+pelikhan@users.noreply.github.com>

* Fix linter error in copilot_sdk_engine_test.go

Co-authored-by: pelikhan <4175913+pelikhan@users.noreply.github.com>

* Add copilot-sdk to schema and create example workflow

Co-authored-by: pelikhan <4175913+pelikhan@users.noreply.github.com>

* Remove stdin support from copilot-client, only use GH_AW_COPILOT_CONFIG env var

Co-authored-by: pelikhan <4175913+pelikhan@users.noreply.github.com>

* Move copilot-sdk example to dev.md and delete example-copilot-sdk.md

Co-authored-by: pelikhan <4175913+pelikhan@users.noreply.github.com>

* Mark copilot-sdk engine as experimental

Co-authored-by: pelikhan <4175913+pelikhan@users.noreply.github.com>

* Update dev.md to use copilot-sdk engine with daily status report workflow

Co-authored-by: pelikhan <4175913+pelikhan@users.noreply.github.com>

* Update copilot_sdk_engine.go

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* Create smoke-copilot-sdk.md workflow and remove dev.md

Co-authored-by: pelikhan <4175913+pelikhan@users.noreply.github.com>

* Restore dev.md as daily status report with copilot-sdk engine

Co-authored-by: pelikhan <4175913+pelikhan@users.noreply.github.com>

* Fix test assertions for copilot-sdk engine registration (#15695)

* Change SupportsLLMGateway to return port number instead of boolean

Co-authored-by: pelikhan <4175913+pelikhan@users.noreply.github.com>

* Simplify BaseEngine SupportsLLMGateway to always return -1

Co-authored-by: pelikhan <4175913+pelikhan@users.noreply.github.com>

* Recompile all workflows after merging main

Co-authored-by: pelikhan <4175913+pelikhan@users.noreply.github.com>

* Change copilot-sdk CLI port from 3312 to 10002 and fail on config marshal error

Co-authored-by: pelikhan <4175913+pelikhan@users.noreply.github.com>

* Remove invalid --api-proxy-port flag from AWF commands

Co-authored-by: pelikhan <4175913+pelikhan@users.noreply.github.com>

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Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: pelikhan <4175913+pelikhan@users.noreply.github.com>
Co-authored-by: Peli de Halleux <pelikhan@users.noreply.github.com>
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: 3 people