fix: resolve CI mypy type checking issues

src/patternforge/template.py

@@ -158,7 +158,8 @@ class {{ class_name }} {
         if not path.exists():
             return None
         with open(path) as f:
-            return yaml.safe_load(f)
+            result = yaml.safe_load(f)
+            return result if isinstance(result, dict) else None
 
     def remove_template(self, name: str) -> bool:
         path = self._get_template_path(name)
@@ -208,10 +209,10 @@ class {{ class_name }} {
                 with open(dst, "w") as f:
                     yaml.dump(data, f, default_flow_style=False)
         else:
-            for f in src.glob("*.yaml"):
-                with open(f) as fp:
+            for yaml_file in src.glob("*.yaml"):
+                with open(yaml_file) as fp:
                     data = yaml.safe_load(fp)
-                out_path = dst / f.name
+                out_path = dst / yaml_file.name
                 if format == "json":
                     with open(out_path.with_suffix(".json"), "w") as fp:
                         json.dump(data, fp, indent=2)