feat: per-position camera settings, material alias dialog, product delete, media browser links

- Per-render-position focal_length_mm/sensor_width_mm (DB → pipeline → Blender)
- FOV-based camera distance with min clamp fix for wide-angle lenses
- Unmapped materials blocking dialog on "Dispatch Renders" with batch alias creation
- Material check endpoint (GET /orders/{id}/check-materials)
- Batch alias endpoint (POST /materials/batch-aliases)
- Quick-map "No alias" badges on Materials page
- Full product hard-delete with storage cleanup (MinIO + disk files + orphaned CadFile)
- Delete button on ProductDetail page with confirmation
- Clickable product names in Media Browser (links to product page)
- Single-line render dispatch/retry (POST /orders/{id}/lines/{id}/dispatch-render)

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

backend/app/services/step_processor.py

@@ -891,6 +891,8 @@ def render_to_file(
     order_line_id: str | None = None,
     usd_path: "Path | None" = None,
     tessellation_engine: str | None = None,
+    focal_length_mm: float | None = None,
+    sensor_width_mm: float | None = None,
 ) -> tuple[bool, dict]:
     """Render a STEP file to a specific output path using current system settings.
 
@@ -1027,6 +1029,8 @@ def render_to_file(
                     log_callback=_log_cb,
                     usd_path=usd_path,
                     tessellation_engine=tessellation_engine or settings["tessellation_engine"],
+                    focal_length_mm=focal_length_mm,
+                    sensor_width_mm=sensor_width_mm,
                 )
                 rendered_png = tmp_png if tmp_png.exists() else None
             except Exception as exc: