feat: Add core rules

scripts/add_css.py

@@ -0,0 +1,22 @@
+#!/usr/bin/env python3
+"""Prepend a book-page.css link to every HTML file in html2/."""
+
+from pathlib import Path
+
+CSS_LINK = '<link rel="stylesheet" href="book-page.css">\n'
+HTML2_DIR = Path(__file__).parent.parent / "html2"
+
+
+def main():
+    files = sorted(HTML2_DIR.glob("*.html"), key=lambda p: int(p.stem) if p.stem.isdigit() else -1)
+    for path in files:
+        content = path.read_text(encoding="utf-8")
+        if CSS_LINK.strip() not in content:
+            path.write_text(CSS_LINK + content, encoding="utf-8")
+            print(f"updated {path.name}")
+        else:
+            print(f"skipped {path.name} (already has link)")
+
+
+if __name__ == "__main__":
+    main()