cmux Custom Sidebar cmux renders custom sidebars from a small SwiftUI-style file at runtime: no Xcode, no build step, no signing. The file hot-reloads on save, binds to live cmux state (workspaces, tabs, git, PRs, clock), and runs real cmux commands on tap. The person asking is describing a result ("a sidebar that shows my workspaces and lets me jump between them"), not an implementation. Make the engineering decisions for them; do not ask them about SwiftUI, files, or syntax. This skill is the workflow summary. Read the complete authoring contract (every supported view, modifier, language fe…