feat(frontend): group product selector by category in routine step forms

Products in the Add/Edit step dropdowns are now grouped by category
(Cleanser → Serum → Moisturizer → …) using SelectGroup/SelectGroupHeading,
and sorted alphabetically by brand then name within each group.

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

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

@@ -10,7 +10,14 @@
 	import { Card, CardContent, CardHeader, CardTitle } from '$lib/components/ui/card';
 	import { Input } from '$lib/components/ui/input';
 	import { Label } from '$lib/components/ui/label';
-	import { Select, SelectContent, SelectItem, SelectTrigger } from '$lib/components/ui/select';
+	import {
+		Select,
+		SelectContent,
+		SelectGroup,
+		SelectGroupHeading,
+		SelectItem,
+		SelectTrigger
+	} from '$lib/components/ui/select';
 	import { Separator } from '$lib/components/ui/separator';
 
 	let { data, form }: { data: PageData; form: ActionData } = $props();
@@ -103,6 +110,34 @@
 	let selectedProductId = $state('');
 
 	const GROOMING_ACTIONS: GroomingAction[] = ['shaving_razor', 'shaving_oneblade', 'dermarolling'];
+
+	const CATEGORY_ORDER = [
+		'cleanser', 'toner', 'essence', 'serum', 'moisturizer',
+		'spf', 'mask', 'exfoliant', 'spot_treatment', 'oil',
+		'hair_treatment', 'tool', 'other'
+	];
+
+	function formatCategory(cat: string): string {
+		return cat.charAt(0).toUpperCase() + cat.slice(1).replace(/_/g, ' ');
+	}
+
+	const groupedProducts = $derived.by(() => {
+		const groups = new Map<string, typeof products>();
+		for (const p of products) {
+			const key = p.category ?? 'other';
+			if (!groups.has(key)) groups.set(key, []);
+			groups.get(key)!.push(p);
+		}
+		for (const list of groups.values()) {
+			list.sort((a, b) => {
+				const b_cmp = (a.brand ?? '').localeCompare(b.brand ?? '');
+				return b_cmp !== 0 ? b_cmp : a.name.localeCompare(b.name);
+			});
+		}
+		return CATEGORY_ORDER
+			.filter((c) => groups.has(c))
+			.map((c) => [c, groups.get(c)!] as const);
+	});
 </script>
 
 <svelte:head><title>Routine {routine.routine_date} {routine.part_of_day.toUpperCase()} — innercontext</title></svelte:head>
@@ -150,8 +185,13 @@
 									{/if}
 								</SelectTrigger>
 								<SelectContent>
-									{#each products as p (p.id)}
+									{#each groupedProducts as [cat, items]}
-										<SelectItem value={p.id}>{p.name} ({p.brand})</SelectItem>
+										<SelectGroup>
+											<SelectGroupHeading>{formatCategory(cat)}</SelectGroupHeading>
+											{#each items as p (p.id)}
+												<SelectItem value={p.id}>{p.name} · {p.brand}</SelectItem>
+											{/each}
+										</SelectGroup>
 									{/each}
 								</SelectContent>
 							</Select>
@@ -202,8 +242,13 @@
 												{/if}
 											</SelectTrigger>
 											<SelectContent>
-												{#each products as p (p.id)}
+												{#each groupedProducts as [cat, items]}
-													<SelectItem value={p.id}>{p.name} ({p.brand})</SelectItem>
+													<SelectGroup>
+														<SelectGroupHeading>{formatCategory(cat)}</SelectGroupHeading>
+														{#each items as p (p.id)}
+															<SelectItem value={p.id}>{p.name} · {p.brand}</SelectItem>
+														{/each}
+													</SelectGroup>
 												{/each}
 											</SelectContent>
 										</Select>