fix(claude): inject COPILOT_GITHUB_TOKEN, scope ANTHROPIC_BASE_URL to Anthropic provider, fix provider-aware api-proxy reflect check, convert Copilot env vars to Anthropic vars in harness, fix smoke model for reasoning effort, and mark model-provider: ...

fix(claude): inject COPILOT_GITHUB_TOKEN, scope ANTHROPIC_BASE_URL to Anthropic provider, fix provider-aware api-proxy reflect check, convert Copilot env vars to Anthropic vars in harness, fix smoke model for reasoning effort, and mark model-provider: ... #19233