Sync third-party and MCP marketplace plugins

Constraint: Public skills are published only by explicit administrator action unless they are tracked third-party market sources.
Confidence: high
Scope-risk: narrow
Directive: Keep private/internal skills out of the public marketplace and preserve normal incremental market Git history.
Tested: Marketplace validation passed.

config/skill-overrides/common/render_pdf.py

@@ -0,0 +1,29 @@
+"""Render PDF pages without Poppler; requires PyMuPDF."""
+
+import argparse
+from pathlib import Path
+
+import pymupdf
+
+
+def convert(pdf_path, output_dir, max_dim=1600):
+    if max_dim <= 0:
+        raise ValueError("max_dim must be positive")
+    output = Path(output_dir)
+    output.mkdir(parents=True, exist_ok=True)
+    with pymupdf.open(pdf_path) as document:
+        for index, page in enumerate(document):
+            scale = min(max_dim / page.rect.width, max_dim / page.rect.height)
+            pixmap = page.get_pixmap(matrix=pymupdf.Matrix(scale, scale), alpha=False)
+            target = output / f"page_{index + 1}.png"
+            pixmap.save(str(target))
+            print(target)
+
+
+if __name__ == "__main__":
+    parser = argparse.ArgumentParser(description=__doc__)
+    parser.add_argument("input")
+    parser.add_argument("output")
+    parser.add_argument("--max-dim", type=int, default=1600)
+    args = parser.parse_args()
+    convert(args.input, args.output, args.max_dim)