Fix mypy type errors in reporting module

src/py_dvt_ate/reporting/charts/matplotlib_charts.py

@@ -6,6 +6,7 @@ Charts are rendered to base64-encoded PNG images for embedding in HTML/PDF.
 
 import base64
 from io import BytesIO
+from typing import Any
 
 import pandas as pd
 
@@ -27,9 +28,9 @@ class ChartGenerator:
             dpi: Resolution for chart images (dots per inch).
         """
         self.dpi = dpi
-        self._plt: type | None = None
+        self._plt: tuple[Any, Any] | None = None
 
-    def _get_matplotlib(self) -> tuple:
+    def _get_matplotlib(self) -> tuple[Any, Any]:
         """Lazy-load matplotlib to avoid import errors when not installed.
 
         Returns:

src/py_dvt_ate/reporting/renderers/pdf.py

@@ -75,7 +75,8 @@ class PDFRenderer:
         """
         try:
             HTML = self._get_weasyprint()
-            return HTML(string=html).write_pdf()
+            result: bytes = HTML(string=html).write_pdf()
+            return result
         except PDFConversionError:
             raise
         except Exception as e: