Use Word VM PDF converter instead of raw LibreOffice in base handler

_convert_to_pdf() now calls pdf_converter.convert_to_pdf() which tries
the Windows Word VM via MinIO first (pixel-perfect), falling back to
LibreOffice headless automatically when the VM is unavailable.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

scripts/workers/services/base_handler.py

@@ -164,33 +164,17 @@ class BaseServiceHandler(ABC):
     # ------------------------------------------------------------------ #
 
     def _convert_to_pdf(self, docx_path: str) -> str:
-        """Convert a DOCX file to PDF using LibreOffice.
+        """Convert a DOCX file to PDF.
+
+        Uses the Word VM via MinIO for pixel-perfect conversion when available,
+        falls back to LibreOffice headless automatically.
 
         Returns the path to the generated PDF file.
         """
-        output_dir = str(Path(docx_path).parent)
-        result = subprocess.run(
-            [
-                "libreoffice",
-                "--headless",
-                "--convert-to",
-                "pdf",
-                "--outdir",
-                output_dir,
-                docx_path,
-            ],
-            capture_output=True,
-            text=True,
-            timeout=120,
-        )
-        if result.returncode != 0:
-            raise RuntimeError(
-                f"LibreOffice conversion failed: {result.stderr}"
-            )
+        from scripts.document_gen.pdf_converter import convert_to_pdf
 
-        pdf_path = str(Path(docx_path).with_suffix(".pdf"))
-        if not Path(pdf_path).exists():
-            raise FileNotFoundError(f"PDF not generated: {pdf_path}")
+        pdf_path_obj = convert_to_pdf(docx_path)
+        pdf_path = str(pdf_path_obj)
 
         logger.info("Converted %s → %s", docx_path, pdf_path)
         return pdf_path