feat(mcp): add Codex client configuration

[TheodoreSpeaks]

Summary

• Add ready-to-paste Codex configuration for public and API-key-protected workflow MCP servers.
• Document Codex setup and add TOML syntax highlighting while preserving Claude Code support.

Type of Change

• Bug fix
• New feature
• Breaking change
• Documentation
• Other: ___________

Testing

• bun run lint
• bun run check:audits
• bun run apps/sim/scripts/check-block-registry.ts origin/staging
• bun run docs-manifest:check
• Affected workspace type checks
• bunx vitest run packages/emcn/src/components/code/code.test.tsx

Checklist

• Code follows project style guidelines
• Self-reviewed my changes
• Tests added/updated and passing
• No new warnings introduced
• I confirm that I have read and agree to the terms outlined in the Contributor License Agreement (CLA)

Screenshots/Videos

Not included; the settings surface requires an authenticated workspace with an existing workflow MCP server.

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1 Skipped Deployment

Project	Deployment	Actions	Updated (UTC)
docs	Skipped		Aug 27, 2026 5:37pm

[cubic-dev-ai]

No issues found across 6 files

Confidence score: 5/5

• Automated review surfaced no issues in the provided summaries.
• No files require special attention.

_{Re-trigger cubic}

[greptile-apps]

Greptile Summary

This PR adds ready-to-paste Codex configuration for public and API-key-protected workflow MCP servers.

• Adds Codex as a selectable MCP client and generates TOML configuration.
• Restores the permission-gated API-key creation action for private Codex servers.
• Adds TOML syntax highlighting and updates MCP documentation and product content.

Confidence Score: 5/5

The PR appears safe to merge.

The previously reported private Codex setup gap is resolved: authorized users retain the API-key creation action, while the note explains that the resulting key must be assigned to SIM_API_KEY; no blocking failure remains.

Important Files Changed

Filename	Overview
apps/sim/app/workspace/[workspaceId]/settings/components/workflow-mcp-servers/workflow-mcp-servers.tsx	Adds Codex configuration and preserves the existing private-server key-creation path; the previously reported omission is fixed.
packages/emcn/src/components/code/code.tsx	Extends the code viewer’s supported language type with TOML.
packages/emcn/src/components/code/prism.ts	Registers the Prism TOML grammar for the new Codex configuration.
apps/docs/content/docs/en/workflows/deployment/mcp.mdx	Documents Codex configuration and environment-based API-key authentication.

_{Reviews (2): Last reviewed commit: "fix(mcp): keep Codex key creation action" | Re-trigger Greptile}

[TheodoreSpeaks]

@greptile