- User themes from $ZOT_HOME/themes/*.json with partial overrides
(colors, syntax, spinner) and dark/light fallback.
- /settings color-theme picker; selection persisted in config.json.
- Theme-only extensions: extension.json plus theme.json (or
themes/theme.json) load without spawning a subprocess.
- write-zot-themes built-in skill and docs/themes.md.
- README, extensions docs, and embedded docs index updated.