fix(plantes): test plant_variety + seed PlantVariety + formatPlantLabel + migrate.py nettoyage

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/app/seed.py

@@ -6,7 +6,7 @@ import app.models  # noqa
 
 def run_seed():
     from app.models.garden import Garden, GardenCell, Measurement
-    from app.models.plant import Plant
+    from app.models.plant import Plant, PlantVariety
     from app.models.planting import Planting, PlantingEvent
     from app.models.task import Task
     from app.models.tool import Tool
@@ -131,11 +131,24 @@ def run_seed():
 
             plantes = []
             for data in plantes_data:
+                variete = data.pop('variete', None)
                 p = Plant(**data)
                 session.add(p)
                 plantes.append(p)
             session.flush()
 
+            # Créer les variétés pour les plantes qui en avaient une
+            plantes_varietes = [
+                ("Andine Cornue", 0),  # Tomate
+                ("Verte", 1),          # Courgette
+                ("Batavia", 3),        # Laitue
+                ("Nain", 6),           # Haricot
+                ("Mange-tout", 7),     # Pois
+                ("Milan", 15),         # Chou
+            ]
+            for variete_nom, idx in plantes_varietes:
+                session.add(PlantVariety(plant_id=plantes[idx].id, variete=variete_nom))
+
             tomate = plantes[0]
             courgette = plantes[1]