Monaco is 5MB. CodeMirror v6 is great but ramp-up is real. Most embedded code surfaces (config files, inline scripts, agent-authored snippets) don't need an IDE — they need an editor that's lightweight, controlled, and bridgeable.

CodeEditor is a custom editor (no Monaco, no CodeMirror) with syntax-highlight presets, controlled value, and a code_* bridge so agents can read selections and apply edits without screen-scraping.

Render <CodeEditor value language="ts" onChange>. For agent control, attach the code bridge — agents get code_get, code_replace, code_insert_at_line, etc.