fix(shopping): capitalisation 1re lettre — catalogue + migration BDD v0.4.9

- CatalogueModal : cleanForm() capitalise désormais le nom avant envoi API
  (création et modification d'article)
- Migration 005 : met à jour shopping.products.name et
  shopping.list_items.custom_name pour capitaliser les données existantes

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

backend/alembic/versions/005_capitalize_product_names.py

@@ -0,0 +1,34 @@
+"""005 - capitaliser la première lettre des noms produits et articles libres
+
+Revision ID: 005
+Revises: 004
+Create Date: 2026-05-25
+"""
+
+from alembic import op
+
+revision = '005'
+down_revision = '004'
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    op.execute("""
+        UPDATE shopping.products
+        SET name = UPPER(SUBSTRING(name, 1, 1)) || SUBSTRING(name, 2)
+        WHERE name IS NOT NULL
+          AND name != ''
+          AND UPPER(SUBSTRING(name, 1, 1)) || SUBSTRING(name, 2) != name
+    """)
+    op.execute("""
+        UPDATE shopping.list_items
+        SET custom_name = UPPER(SUBSTRING(custom_name, 1, 1)) || SUBSTRING(custom_name, 2)
+        WHERE custom_name IS NOT NULL
+          AND custom_name != ''
+          AND UPPER(SUBSTRING(custom_name, 1, 1)) || SUBSTRING(custom_name, 2) != custom_name
+    """)
+
+
+def downgrade():
+    pass

frontend/src/components/shopping/CatalogueModal.tsx

@@ -85,9 +85,14 @@ export default function CatalogueModal({ stores, onClose }: CatalogueModalProps)
     setError(null)
   }
 
+  function capitalize(s: string): string {
+    const t = s.trim()
+    return t.charAt(0).toUpperCase() + t.slice(1)
+  }
+
   function cleanForm(f: ProductCreate): ProductCreate {
     return {
-      name: f.name.trim(),
+      name: capitalize(f.name),
       brand: f.brand?.trim() || undefined,
       category: f.category?.trim() || undefined,
       description: f.description?.trim() || undefined,