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>

render-worker/scripts/_blender_materials.py

@@ -8,12 +8,45 @@ import time as _time
 FAILED_MATERIAL_NAME = "SCHAEFFLER_059999_FailedMaterial"
 
 
+def _find_material_with_nodes(base_name: str):
+    """Find a material by name that actually has shader nodes.
+
+    Blender's USD importer creates empty stub materials (use_nodes=True,
+    node_tree has 0 nodes) from USD material bindings.  When we later
+    append the real material from a .blend library, Blender renames it
+    with a .001/.002 suffix to avoid the name collision.
+
+    This helper searches bpy.data.materials for the version that has
+    actual shader nodes, preferring exact name match, then .NNN suffixes.
+    """
+    import bpy  # type: ignore[import]
+
+    # Exact name first
+    exact = bpy.data.materials.get(base_name)
+    if exact and exact.node_tree and len(exact.node_tree.nodes) > 0:
+        return exact
+
+    # Search for .NNN suffixed versions
+    for mat in bpy.data.materials:
+        if not mat.name.startswith(base_name):
+            continue
+        suffix = mat.name[len(base_name):]
+        if suffix == "" or _re.match(r'^\.\d{3}$', suffix):
+            if mat.node_tree and len(mat.node_tree.nodes) > 0:
+                return mat
+    return None
+
+
 def _batch_append_materials(mat_lib_path: str, names: set[str]) -> dict:
     """Append multiple materials from a .blend file in a single open.
 
     Uses bpy.data.libraries.load() to open the .blend once instead of
     N separate bpy.ops.wm.append() calls (each reopens the file).
     Falls back to individual append for any materials that fail to load.
+
+    Handles empty material stubs left by Blender's USD importer: when a
+    stub exists with the target name, the library material gets renamed
+    with a .NNN suffix.  We find it via _find_material_with_nodes().
     """
     import bpy  # type: ignore[import]
 
@@ -28,12 +61,16 @@ def _batch_append_materials(mat_lib_path: str, names: set[str]) -> dict:
             to_load = [n for n in names if n in available]
             not_found = names - available
             data_to.materials = to_load
-        # After the context manager closes, materials are loaded into bpy.data
+        # After the context manager closes, materials are loaded into bpy.data.
+        # If a USD stub occupied the name, the real material gets a .NNN suffix.
         for mat_name in to_load:
-            mat = bpy.data.materials.get(mat_name)
+            mat = _find_material_with_nodes(mat_name)
             if mat:
                 result[mat_name] = mat
-                print(f"[blender_render] batch-appended material: {mat_name}")
+                if mat.name != mat_name:
+                    print(f"[blender_render] batch-appended material: {mat_name} (as '{mat.name}', stub collision)")
+                else:
+                    print(f"[blender_render] batch-appended material: {mat_name}")
             else:
                 print(f"[blender_render] WARNING: material '{mat_name}' not found after batch append")
         if not_found:
@@ -51,7 +88,7 @@ def _batch_append_materials(mat_lib_path: str, names: set[str]) -> dict:
                     filename=mat_name,
                     link=False,
                 )
-                mat = bpy.data.materials.get(mat_name)
+                mat = _find_material_with_nodes(mat_name)
                 if mat:
                     result[mat_name] = mat
             except Exception:
@@ -141,11 +178,15 @@ def apply_material_library_direct(
     # Batch-append materials from library (single file open)
     appended: dict = {}
     _t_append = _time.monotonic()
-    # Check already-loaded materials first
+    # Check already-loaded materials first — but skip empty stubs created by
+    # Blender's USD importer (use_nodes=True but node_tree has 0 nodes).
+    # Those stubs must be loaded from the library via _batch_append_materials
+    # which uses _find_material_with_nodes() to resolve stub collisions.
     still_needed = set()
     for mat_name in needed:
-        if mat_name in bpy.data.materials:
-            appended[mat_name] = bpy.data.materials[mat_name]
+        existing = _find_material_with_nodes(mat_name)
+        if existing:
+            appended[mat_name] = existing
         else:
             still_needed.add(mat_name)
     # Load remaining from .blend in one pass