fix: rack elevations missing in all export formats

RackElevationSVG falls back to RACK_ELEVATION_DEFAULT_* config
parameters, which raise AttributeError on the target NetBox version.
Pass the dimensions explicitly instead.

Add a Pillow-based PNG rack renderer (role colors, unit legend,
full-depth devices shown dimmed from the other side). It is used for
Word when cairosvg is unavailable and replaces a failed SVG in all
formats.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

netbox_customer_export/rack_svg.py

@@ -6,6 +6,12 @@ from netbox.plugins import get_plugin_config
 
 logger = logging.getLogger("netbox_customer_export")
 
+# NetBox-Standardwerte der Rack-Ansicht
+UNIT_WIDTH = 220
+UNIT_HEIGHT = 22
+LEGEND_WIDTH = 30
+MARGIN_WIDTH = 15
+
 
 def render_rack_svg(rack, face, user):
     """Gibt (svg, fehler) zurück – genau einer der beiden Werte ist None.
@@ -21,7 +27,18 @@ def render_rack_svg(rack, face, user):
         else:
             from dcim.svg import RackElevationSVG
 
-            svg = RackElevationSVG(rack, user=user, include_images=False, base_url="").render(face)
+            # Maße explizit übergeben: je nach NetBox-Version fehlen die RACK_ELEVATION_DEFAULT_*-Parameter
+            # in der Konfiguration, dann bricht der Renderer mit AttributeError ab.
+            svg = RackElevationSVG(
+                rack,
+                unit_width=UNIT_WIDTH,
+                unit_height=UNIT_HEIGHT,
+                legend_width=LEGEND_WIDTH,
+                margin_width=MARGIN_WIDTH,
+                user=user,
+                include_images=False,
+                base_url="",
+            ).render(face)
         return (svg.tostring() if hasattr(svg, "tostring") else str(svg)), None
     except Exception as e:  # noqa: BLE001 – ein defektes Rack soll nicht den ganzen Export abbrechen
         logger.exception("Rack-SVG für %s (%s) fehlgeschlagen", rack, face)