Adds a `github-copilot` LLM provider backed by the official GitHub Copilot SDK, using the signed-in Copilot entitlement with no `HINDSIGHT_API_LLM_API_KEY`.
Verified end-to-end against a live Copilot subscription: retain, consolidation and reflect all run on the provider.
Review fixes on top of the original submission:
- default to `gpt-5.6-terra`; the submitted `gpt-5.6-sol` is not in the model list the runtime serves, so every call failed and the provider was unusable out of the box
- make a rejected request configuration terminal instead of a runtime failure; an unavailable model was invalidating the shared runtime and respawning `copilot --headless` once per attempt (5 spawns at max_retries=3, ~12 at the default of 10)
- let a token-authenticated host run without `~/.copilot`, so the documented COPILOT_GITHUB_TOKEN / GH_TOKEN / GITHUB_TOKEN path works in containers and CI
- regenerate skills/hindsight-docs (the provider list also feeds the generated faq.md)
Co-authored-by: Max Marino <dudujuju828@users.noreply.github.com>
Max Marino