fix: repair Rentman equipment sync with real API field mapping

- Map real Rentman fields: price -> rental_price, folder -> category/subcategory
  (resolved via folder hierarchy to top-level categories), code -> number,
  shop_description_long (fallback short/external_remark) -> description (HTML stripped)
- Sync only in_shop items; exclude archived/temporary from public catalog
- Extract known brands from equipment names (d&b, Shure, Pioneer, ...)
- Build specifications from physical fields (power, weight, dimensions)
- Persist equipment images in docker volume (survive redeploys)
- Router: filter available items, add price_asc/price_desc sorting
- Frontend: show prices in catalog card, detail page and cart with
  per-day subtotal; price sorting options
- Tests: use real Rentman field names in fixtures, mock folder_map

backend/tests/test_rentman_import.py

@@ -10,31 +10,63 @@ from app.services.rentman_service import RentmanService
 
 
 def make_raw_equipment(rid: str, name: str, category: str = "Lautsprecher") -> dict:
+    """Raw equipment item using REAL Rentman API field names."""
     return {
         "id": rid,
         "name": name,
-        "number": f"{name[:3].upper()}-001",
+        "displayname": name,
         "code": f"{name[:3].upper()}-001",
-        "equipment_group": {"name": category},
-        "description": f"Description for {name}",
-        "specifications": {"weight": 50, "power": 750},
-        "images": [{"url": f"https://example.com/{rid}.jpg"}],
+        "folder": f"/folders/{int(rid) % 5 + 1}",
+        "shop_description_long": f"<p>Description for {name}</p>",
+        "external_remark": "",
+        "power": 750,
+        "weight": 50,
+        "empty_weight": 50,
+        "image": f"/files/{rid}",
+        "price": 150.00,
+        "in_shop": True,
+        "in_archive": False,
+        "temporary": False,
+        "updateHash": f"hash-{rid}",
+    }
+
+
+def make_transformed(raw: dict, folder_map=None) -> dict:
+    """Transformed equipment dict as produced by the real Rentman mapping (no network)."""
+    return {
+        "rentman_id": str(raw["id"]),
+        "name": raw["name"],
+        "number": raw.get("code", ""),
+        "category": "Tontechnik",
+        "subcategory": "Mikrofone",
+        "description": f"Description for {raw['name']}",
+        "specifications": None,
+        "images": [],
         "rental_price": 150.00,
-        "brand": "L-Acoustics",
+        "brand": "",
         "available": True,
+        "update_hash": raw.get("updateHash", ""),
     }
 
 
 @pytest.mark.asyncio
 async def test_transform_equipment():
-    raw = make_raw_equipment("42", "K2 Line Array", "Lautsprecher")
-    result = RentmanService.transform_equipment(raw)
+    raw = make_raw_equipment("42", "Shure SM58 Mikrofon dynamisch")
+    service = RentmanService.__new__(RentmanService)  # no network on init path
+    folder_map = {
+        f"/folders/{42 % 5 + 1}": {"category": "Tontechnik", "subcategory": "Mikrofone"},
+    }
+    with patch.object(RentmanService, "get_file_url", new=AsyncMock(return_value="https://example.com/42.jpg")):
+        result = await service.transform_equipment(raw, folder_map=folder_map)
     assert result["rentman_id"] == "42"
-    assert result["name"] == "K2 Line Array"
-    assert result["category"] == "Lautsprecher"
-    assert result["images"] == ["https://example.com/42.jpg"]
-    assert result["brand"] == "L-Acoustics"
+    assert result["name"] == "Shure SM58 Mikrofon dynamisch"
+    assert result["category"] == "Tontechnik"
+    assert result["subcategory"] == "Mikrofone"
+    assert result["rental_price"] == 150.00
+    assert result["brand"] == "Shure"
     assert result["available"] is True
+    assert result["description"] == "Description for Shure SM58 Mikrofon dynamisch"
+    assert result["images"] == ["https://example.com/42.jpg"]
 
 
 @pytest.mark.asyncio
@@ -49,6 +81,8 @@ async def test_paginated_import(test_db):
     mock_rentman.get_all_equipment = AsyncMock(return_value=[
         *[make_raw_equipment(str(i), f"Item {i}") for i in range(250)]
     ])
+    mock_rentman.get_folder_map = AsyncMock(return_value={})
+    mock_rentman.transform_equipment = AsyncMock(side_effect=make_transformed)
 
     with patch("app.services.sync_service.cache") as mock_cache:
         mock_cache.delete_pattern = AsyncMock(return_value=0)
@@ -83,6 +117,8 @@ async def test_sync_upsert_existing(test_db):
     mock_rentman.get_all_equipment = AsyncMock(return_value=[
         make_raw_equipment("100", "New Name", "Lautsprecher")
     ])
+    mock_rentman.get_folder_map = AsyncMock(return_value={})
+    mock_rentman.transform_equipment = AsyncMock(side_effect=make_transformed)
 
     with patch("app.services.sync_service.cache") as mock_cache:
         mock_cache.delete_pattern = AsyncMock(return_value=0)