fix(report_engine): lazy-init output dir to fix CI PermissionError on /app

backend/app/services/report_engine.py

@@ -31,7 +31,7 @@ class ReportEngine:
 
     # Define function __init__
     def __init__(self) -> None:
-        """Initialise the Jinja2 environment and ensure the output directory exists."""
+        """Initialise the Jinja2 environment."""
         # Assign self.jinja_env = Environment(
         self.jinja_env = Environment(
             # Keyword argument: loader
@@ -39,7 +39,8 @@ class ReportEngine:
             # Keyword argument: autoescape
             autoescape=True,
         )
-        # Call os.makedirs()
+
+    def _ensure_output_dir(self) -> None:
         os.makedirs(settings.REPORT_OUTPUT_DIR, exist_ok=True)
 
     # Define function render_html
@@ -57,6 +58,7 @@ class ReportEngine:
     # Define function generate_pdf
     def generate_pdf(self, template_name: str, context: dict) -> str:
         """Render HTML and convert to PDF with WeasyPrint."""
+        self._ensure_output_dir()
         # Import CSS, HTML from weasyprint
         from weasyprint import CSS, HTML
 
@@ -93,6 +95,7 @@ class ReportEngine:
     # Define function generate_docx
     def generate_docx(self, template_name: str, context: dict) -> str:
         """Render a .docx template with docxtpl."""
+        self._ensure_output_dir()
         # Import DocxTemplate from docxtpl
         from docxtpl import DocxTemplate
 
@@ -131,6 +134,7 @@ class ReportEngine:
     # Define function generate_html_file
     def generate_html_file(self, template_name: str, context: dict) -> str:
         """Render and save a standalone HTML report."""
+        self._ensure_output_dir()
         # Assign html_content = self.render_html(template_name, context)
         html_content = self.render_html(template_name, context)
         # Assign output_path = os.path.join(