feat(fase-5.10.0): drop shopping_items.unit column

The unit field had no edit path under the redesign (only name + qty
remain in the row; the double-tap overlay is name-only). Users can encode
the unit inside the name when it matters — e.g. "Milk 1L", "Eggs 1 doz".

Changes
  supabase/migrations/011_drop_shopping_items_unit.sql — DROP COLUMN
  supabase/seed.sql — unit values folded into names where relevant
  supabase/tests/002_item_frequency_trigger.sql — remove unit from INSERT
  packages/types — remove unit from ShoppingItem Row/Insert/Update
  apps/web/src/lib/stores/lists.ts — addItem/updateItem signatures
  apps/web/src/routes/(app)/lists/[id]/+page.svelte — purge newUnit /
    editUnit state + inputs + display
  apps/web/src/routes/(app)/lists/[id]/session/+page.svelte — simplify
    quantity-only render
  apps/web/messages/{en,es}.json — remove list_unit_label

Verification
  just test-db  → 34 pgTAP green
  just test-integration → 140 + 2 skipped
  just test-unit → 11 green
  just test-e2e → 39 + 2 skipped

The generated search tsvector on shopping_items.search already indexes
only `name`, so full-text search coverage is unchanged.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

apps/web/src/routes/(app)/lists/[id]/+page.svelte

@@ -49,7 +49,6 @@
 	// Add-item form
 	let newName = $state('');
 	let newQty = $state<number | null>(null);
-	let newUnit = $state('');
 	let nameInput: HTMLInputElement | undefined = $state();
 
 	// Suggestions
@@ -60,7 +59,6 @@
 	let editingId = $state<string | null>(null);
 	let editName = $state('');
 	let editQty = $state<number | null>(null);
-	let editUnit = $state('');
 
 	// Swipe-to-delete (touch only)
 	let swipeOffsets = $state<Record<string, number>>({});
@@ -169,7 +167,6 @@
 			list_id: listId,
 			name,
 			quantity: newQty,
-			unit: newUnit.trim() || null,
 			is_checked: false,
 			checked_by: null,
 			checked_at: null,
@@ -188,14 +185,12 @@
 		items = [...items, optimistic];
 		newName = '';
 		newQty = null;
-		newUnit = '';
 		nameInput?.focus();
 
 		const real = await addItem(
 			listId,
 			name,
 			newQty,
-			optimistic.unit,
 			$currentUser.id,
 			sortOrder,
 			tempId
@@ -221,7 +216,6 @@
 					list_id: listId,
 					name,
 					quantity: newQty,
-					unit: optimistic.unit,
 					sort_order: sortOrder,
 					created_by: $currentUser.id
 				}
@@ -268,7 +262,6 @@
 		editingId = item.id;
 		editName = item.name;
 		editQty = item.quantity;
-		editUnit = item.unit ?? '';
 	}
 
 	async function commitEdit(item: ShoppingItem) {
@@ -276,18 +269,12 @@
 		editingId = null;
 		const name = editName.trim();
 		if (!name) return;
-		if (name === item.name && editQty === item.quantity && (editUnit || null) === item.unit) return;
+		if (name === item.name && editQty === item.quantity) return;
 
 		items = items.map((i) =>
-			i.id === item.id
-				? { ...i, name, quantity: editQty, unit: editUnit.trim() || null }
-				: i
+			i.id === item.id ? { ...i, name, quantity: editQty } : i
 		);
-		await updateItem(item.id, {
-			name,
-			quantity: editQty,
-			unit: editUnit.trim() || null
-		});
+		await updateItem(item.id, { name, quantity: editQty });
 	}
 
 	function handleEditKeydown(e: KeyboardEvent, item: ShoppingItem) {
@@ -531,15 +518,6 @@
 												class="w-14 bg-transparent text-sm text-text-secondary outline-none
 													border-b border-slate-300 dark:border-slate-600 pb-0.5 text-right"
 											/>
-											<input
-												type="text"
-												bind:value={editUnit}
-												onblur={() => commitEdit(item)}
-												onkeydown={(e) => handleEditKeydown(e, item)}
-												placeholder={m.list_unit_label()}
-												class="w-14 bg-transparent text-sm text-text-secondary outline-none
-													border-b border-slate-300 dark:border-slate-600 pb-0.5"
-											/>
 										</div>
 									{:else}
 										<!-- Item display -->
@@ -550,9 +528,6 @@
 											<span class="block truncate text-sm text-slate-800 dark:text-slate-200">
 												{item.name}
 											</span>
-											{#if item.unit}
-												<span class="text-[12px] text-text-muted">{item.unit}</span>
-											{/if}
 										</button>
 
 										<!-- Quantity stepper -->
@@ -662,16 +637,9 @@
 						type="number"
 						min="1"
 						placeholder={m.list_qty_label()}
-						class="w-12 bg-transparent text-sm text-text-secondary placeholder:text-text-muted
-							outline-none text-right"
-					/>
-					<input
-						bind:value={newUnit}
-						type="text"
-						placeholder={m.list_unit_label()}
 						onkeydown={handleAddKeydown}
 						class="w-12 bg-transparent text-sm text-text-secondary placeholder:text-text-muted
-							outline-none"
+							outline-none text-right"
 					/>
 				</div>
 				<button

apps/web/src/routes/(app)/lists/[id]/session/+page.svelte

@@ -134,10 +134,8 @@
 							></button>
 							<div class="flex-1 min-w-0">
 								<p class="truncate text-base font-medium">{item.name}</p>
-								{#if item.quantity || item.unit}
-									<p class="text-sm text-text-muted">
-										{item.quantity ?? ''}{item.unit ? ' ' + item.unit : ''}
-									</p>
+								{#if item.quantity}
+									<p class="text-sm text-text-muted">{item.quantity}</p>
 								{/if}
 							</div>
 						</li>