Align add-item form controls to consistent height

Section dropdown and Add button were py-2.5 while QuantityInput uses
py-2, causing a height mismatch. Normalized all controls in the second
row to py-2 and capped the section dropdown width at max-w-36.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/frontend/src/routes/lists/[id]/+page.svelte

@@ -288,7 +288,7 @@
 						type="text"
 						bind:value={newItemQuantityNote}
 						placeholder="e.g. to taste"
-						class="w-36 rounded-lg border border-gray-300 px-2 py-2.5 text-sm focus:border-primary focus:outline-none"
+						class="w-36 rounded-lg border border-gray-300 px-2 py-2 text-sm focus:border-primary focus:outline-none"
 					/>
 				{:else}
 					<QuantityInput
@@ -299,7 +299,7 @@
 				{#if sections.length > 0}
 					<select
 						bind:value={newItemSectionId}
-						class="rounded-lg border border-gray-300 bg-white px-2 py-2.5 text-sm focus:border-primary focus:outline-none"
+						class="max-w-36 rounded-lg border border-gray-300 bg-white px-2 py-2 text-sm focus:border-primary focus:outline-none"
 						aria-label="Section"
 					>
 						<option value={null}>Uncategorized</option>
@@ -310,7 +310,7 @@
 				{/if}
 				<button
 					type="submit"
-					class="rounded-lg bg-primary px-4 py-2.5 font-semibold text-white"
+					class="rounded-lg bg-primary px-4 py-2 font-semibold text-white"
 				>
 					Add
 				</button>