🤖 refactor: update VS Code extension branding and marketplace publishing

[ammar-agent]

Summary

Updates the VS Code extension branding from "cmux" to "mux" and adds automated marketplace publishing to the release workflow.

Changes

Branding Updates

• Extension metadata: Updated name, displayName, and description in package.json
• Command IDs: Changed from cmux.* to mux.* (e.g., mux.openWorkspace)
• User-facing strings: Updated error messages, UI text, and console logs
• Domain reference: Fixed to use correct live domain cmux.io
• Keywords: Updated marketplace keywords from "cmux" to "mux"

GitHub Workflows

• Artifact naming: Changed from cmux-*.vsix to mux-*.vsix in build and release workflows
• Marketplace publishing: Added automatic publishing to VS Code marketplace on release
  • Requires VSCE_PAT secret to be set in repository settings
  • Only publishes if token is available (graceful degradation)
• Workflow descriptions: Updated composite action descriptions

Marketplace Setup

To enable marketplace publishing, add the VSCE_PAT secret to repository settings:

1. Create a Personal Access Token in Azure DevOps:

   • Go to https://dev.azure.com → Profile → Personal access tokens
   • Create token with Marketplace (Manage) scope
   • Set expiration (90 days recommended)

2. Add to GitHub repository:

   • Go to repository Settings → Secrets and variables → Actions
   • Create new secret: VSCE_PAT with your token value

The extension will automatically publish to the marketplace when a new release is created.

Testing

• ✅ Extension builds successfully with new naming
• ✅ GitHub workflows updated for new artifact names
• ✅ All user-facing text updated to "mux" branding
• ✅ Domain reference points to correct cmux.io

Generated with mux