fix(api): correct specification field name in material search

.qwen/settings.json

@@ -0,0 +1,8 @@
+{
+  "permissions": {
+    "allow": [
+      "Bash(git add *)",
+      "Bash(git commit *)"
+    ]
+  }
+}

inventory-backend/app/api/v1/bom.py

@@ -328,7 +328,7 @@ def get_material_base_list():
             query = query.filter(
                 or_(
                     MaterialBase.name.ilike(f"%{keyword}%"),
-                    MaterialBase.spec.ilike(f"%{keyword}%")
+                    MaterialBase.spec_model.ilike(f"%{keyword}%")
                 )
             )