feat: absorb caozhiyuan/copilot-api upstream changes

[Copilot]

Absorbs all new features and refactors from caozhiyuan/copilot-api (2025-10 → 2026-03) that diverged after the last merge. BlueSkyXN-specific customizations (APP_NAME branding, --all-agent flag) are preserved.

New endpoints

• /v1/responses — OpenAI Responses API with streaming support
• /:provider/v1/messages + /:provider/v1/models — multi-provider Anthropic proxy routes

New infrastructure

• src/lib/config.ts — JSON AppConfig (model settings, extra prompts, provider configs, context management, etc.)
• src/lib/logger.ts — structured request/response logger
• src/lib/models.ts — model registry and normalization
• src/lib/trace.ts — trace-ID middleware
• src/lib/request-auth.ts / request-context.ts — per-request auth and context
• src/services/copilot/create-messages.ts — native Copilot /v1/messages service
• src/services/copilot/create-responses.ts — Responses API service
• src/services/providers/anthropic-proxy.ts — Anthropic provider proxy
• src/routes/messages/subagent-marker.ts — __SUBAGENT_MARKER__ / x-session-id propagation

Routing improvements

• Claude-family models prefer Copilot's native /v1/messages over chat completions, enabling interleaved-thinking, advanced-tool-use, and context-management betas
• Phase-aware gpt-5.4 / gpt-5.3-codex commentary before tool calls
• GPT context compaction via responsesApiContextManagementModels
• Tool-less warmup requests routed to smallModel to avoid wasting premium quota

CLI / auth additions

• --enterprise-url / COPILOT_API_ENTERPRISE_URL for GHE.com
• --oauth-app=opencode / COPILOT_API_OAUTH_APP
• --api-home / COPILOT_API_HOME for custom data directory

Other upstream fixes

• HTTP 429 retry headers forwarded to callers
• Tool schema properties normalization for OpenAI API
• User ID parsing with JSON + legacy fallback
• Machine ID caching; VSCode session refresh
• Accurate Claude token counting via Anthropic's free endpoint

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• https://api.github.com/repos/caozhiyuan/copilot-api/commits
  • Triggering command: /home/REDACTED/work/_temp/ghcca-node/node/bin/node /home/REDACTED/work/_temp/ghcca-node/node/bin/node --enable-source-maps /home/REDACTED/work/_temp/copilot-developer-action-main/dist/index.js (http block)
• https://api.github.com/repos/caozhiyuan/copilot-api/contents/src/lib
  • Triggering command: /usr/bin/curl curl -sL REDACTED (http block)
• https://api.github.com/repos/caozhiyuan/copilot-api/contents/src/routes
  • Triggering command: /usr/bin/curl curl -sL REDACTED (http block)
• https://api.github.com/repos/caozhiyuan/copilot-api/contents/src/services
  • Triggering command: /usr/bin/curl curl -sL REDACTED (http block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)