chore: add code execution as gateway mode

[tlgimenes]

What is this contribution about?

Describe your changes and why they're needed.

Screenshots/Demonstration

Add screenshots or a Loom video if your changes affect the UI.

Review Checklist

• PR title is clear and descriptive
• Changes are tested and working
• Documentation is updated (if needed)
• No breaking changes

---

Summary by cubic

Add sandboxed JavaScript execution via QuickJS and enable the code_execution gateway strategy with a new GATEWAY_RUN_CODE tool for running code that calls other tools. Includes a hardened runtime with timeouts, console capture, and structured JSON results.

• New Features

  • QuickJS sandbox: memory/stack limits, interrupt-based timeouts, console.log/warn/error capture, error inspection, and a host-bridge to call tools. Code runs as an ES module that export default async (tools) => { … }.
  • Gateway strategy: implements code_execution exposing GATEWAY_SEARCH_TOOLS, GATEWAY_DESCRIBE_TOOLS, and GATEWAY_RUN_CODE with Zod-validated inputs and consistent JSON result/error helpers.
  • Dependencies: add quickjs-emscripten-core and @jitl/quickjs-wasmfile-release-sync. Minor UI polish for integration icons and single-line gateway descriptions.

• Bug Fixes

  • models:stream now assigns the MCP client before use and closes the correct client in onError/onFinish.
  • LLM provider logs now include the raw chunk on stream parse failures for easier debugging.

^{Written for commit f7ec0f0. Summary will update automatically on new commits.}

[github-actions]

Release Options

Should a new version be published when this PR is merged?

React with an emoji to vote on the release type:

Reaction	Type	Next Version
👍	Prerelease	1.0.0-alpha.36
🎉	Patch	1.0.1
❤️	Minor	1.1.0
🚀	Major	2.0.0

Current version: 1.0.0-alpha.35

Deployment

• Deploy to production (triggers ArgoCD sync after Docker image is published)

[cubic-dev-ai]

No issues found across 13 files