Fix code blocks + add violet bg classes to tw.css

- Pass :code keyword to ~doc-code and ~example-source components
  (highlighted content was positional but components use &key code)
- Rebuild tw.css (v3.4.19) with sx/sxc and sx/content in content paths
  so highlight.py classes (text-violet-600, text-rose-600, etc.) are included
- Add bg-violet-{100-500} classes for the sx app's violet menu bar
- Add highlight.py custom syntax highlighter (sx, python, bash)

IMPORTANT: tw.css must contain bg-violet-{100-500} rules for the sx
app's menu bar. Do not rebuild tw.css without ensuring violet classes
are included (via safelist or content paths).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

sx/sxc/sx_components.py

@@ -25,13 +25,13 @@ def _full_page(ctx: dict, **kwargs) -> str:
 def _code(code: str, language: str = "lisp") -> str:
     """Build a ~doc-code component with highlighted content."""
     highlighted = highlight(code, language)
-    return f'(~doc-code {highlighted})'
+    return f'(~doc-code :code {highlighted})'
 
 
 def _example_code(code: str) -> str:
     """Build an ~example-source component with highlighted content."""
     highlighted = highlight(code, "lisp")
-    return f'(~example-source {highlighted})'
+    return f'(~example-source :code {highlighted})'
 
 
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