feat(policy): add GitHub Copilot API endpoints to base sandbox policy

[htekdev]

Summary

Adds GitHub Copilot API endpoints to the base sandbox policy, enabling Copilot CLI to run inside OpenShell sandboxes with L7 proxy credential injection.

Changes

New: copilot_api policy

• All endpoints from GitHub's official Copilot allowlist reference:
  • api.githubcopilot.com — default Copilot API
  • api.individual/business/enterprise.githubcopilot.com — subscription-tier routing
  • copilot-proxy.githubusercontent.com — model proxy
  • origin-tracker.githubusercontent.com — tracking
  • telemetry.enterprise.githubcopilot.com — telemetry
  • default.exp-tas.com — feature flags
  • release-assets.githubusercontent.com — binary updates
• L7 inspection enabled (protocol: rest, tls: terminate) on API endpoints for credential injection
• Binary paths: /usr/bin/node, /usr/bin/copilot, /usr/lib/node_modules/**

Updated: github_rest_api policy

• Added node, copilot, and node_modules binary paths so Copilot can access the GitHub API

Updated: github_ssh_over_https policy

• Added node, copilot, node_modules, and git-core binary paths for Copilot git operations

Removed: old copilot policy

• Replaced by the more complete copilot_api policy (old one lacked L7 config, missing subscription-tier endpoints)

Testing

Verified end-to-end in a live OpenShell sandbox:

• Copilot CLI authenticates via proxy credential injection ✅
• /models endpoint returns available models ✅
• /chat/completions inference calls succeed ✅
• /mcp/readonly MCP calls succeed ✅
• Zero policy denials ✅

Related

• NVIDIA/OpenShell PR #476 — Copilot provider support
• NVIDIA/OpenShell Issue #707 — Copilot CLI enum fix
• github/copilot-cli#2431 — Copilot CLI client-side token validation

[htekdev]

Good catch — removed tls: terminate from all Copilot endpoints. TLS detection is automatic now per #544. Updated in latest push.

[htekdev]

Good point — reverted the broad binary additions. The copilot policy now only allows the copilot-specific binary paths (/usr/bin/copilot and the npm-installed copilot binary glob). Removed the /usr/bin/node and /usr/lib/node_modules/** entries to avoid opening up access for arbitrary node apps.

Also reverted the binary additions to github_rest_api and github_ssh_over_https — those stay scoped to their original binaries (claude/gh and git respectively).

[htekdev]

Hold. Pending our CLI to get updated to update the version in the docker image

[htekdev]

@johntmyers This PR is ready for review.