feat(frontend): add PL/EN i18n using @inlang/paraglide-js v2

- Install @inlang/paraglide-js v2 with Vite plugin and paraglideMiddleware hook
- Add messages/pl.json and messages/en.json with ~400 translation keys
- Create project.inlang/settings.json (PL as base locale)
- Add LanguageSwitcher component (cookie-based, no URL prefix needed)
- Replace all hardcoded strings across 14 pages/components with m.*() calls
- ProductForm uses derived label maps for all enum types (category, texture, etc.)

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

frontend/src/routes/health/lab-results/+page.svelte

@@ -1,6 +1,7 @@
 <script lang="ts">
 	import { enhance } from '$app/forms';
 	import type { ActionData, PageData } from './$types';
+	import { m } from '$lib/paraglide/messages.js';
 	import { Badge } from '$lib/components/ui/badge';
 	import { Button } from '$lib/components/ui/button';
 	import { Card, CardContent, CardHeader, CardTitle } from '$lib/components/ui/card';
@@ -34,16 +35,16 @@
 	let filterFlag = $derived(data.flag ?? '');
 </script>
 
-<svelte:head><title>Lab Results — innercontext</title></svelte:head>
+<svelte:head><title>{m["labResults_title"]()} — innercontext</title></svelte:head>
 
 <div class="space-y-6">
 	<div class="flex items-center justify-between">
 		<div>
-			<h2 class="text-2xl font-bold tracking-tight">Lab Results</h2>
-			<p class="text-muted-foreground">{data.results.length} results</p>
+			<h2 class="text-2xl font-bold tracking-tight">{m["labResults_title"]()}</h2>
+			<p class="text-muted-foreground">{m["labResults_count"]({ count: data.results.length })}</p>
 		</div>
 		<Button variant="outline" onclick={() => (showForm = !showForm)}>
-			{showForm ? 'Cancel' : '+ Add result'}
+			{showForm ? m.common_cancel() : m["labResults_addNew"]()}
 		</Button>
 	</div>
 
@@ -51,12 +52,12 @@
 		<div class="rounded-md bg-destructive/10 px-4 py-3 text-sm text-destructive">{form.error}</div>
 	{/if}
 	{#if form?.created}
-		<div class="rounded-md bg-green-50 px-4 py-3 text-sm text-green-700">Result added.</div>
+		<div class="rounded-md bg-green-50 px-4 py-3 text-sm text-green-700">{m["labResults_added"]()}</div>
 	{/if}
 
 	<!-- Filter -->
 	<div class="flex items-center gap-3">
-		<span class="text-sm text-muted-foreground">Flag:</span>
+		<span class="text-sm text-muted-foreground">{m["labResults_flagFilter"]()}</span>
 		<Select
 			type="single"
 			value={filterFlag}
@@ -64,9 +65,9 @@
 				goto(v ? `/health/lab-results?flag=${v}` : '/health/lab-results');
 			}}
 		>
-			<SelectTrigger class="w-32">{filterFlag || 'All'}</SelectTrigger>
+			<SelectTrigger class="w-32">{filterFlag || m["labResults_flagAll"]()}</SelectTrigger>
 			<SelectContent>
-				<SelectItem value="">All</SelectItem>
+				<SelectItem value="">{m["labResults_flagAll"]()}</SelectItem>
 				{#each flags as f (f)}
 					<SelectItem value={f}>{f}</SelectItem>
 				{/each}
@@ -76,40 +77,40 @@
 
 	{#if showForm}
 		<Card>
-			<CardHeader><CardTitle>New lab result</CardTitle></CardHeader>
+			<CardHeader><CardTitle>{m["labResults_newTitle"]()}</CardTitle></CardHeader>
 			<CardContent>
 				<form method="POST" action="?/create" use:enhance class="grid grid-cols-2 gap-4">
 					<div class="space-y-1">
-						<Label for="collected_at">Date *</Label>
+						<Label for="collected_at">{m["labResults_date"]()}</Label>
 						<Input id="collected_at" name="collected_at" type="date" required />
 					</div>
 					<div class="space-y-1">
-						<Label for="test_code">LOINC code * <span class="text-xs text-muted-foreground">(e.g. 718-7)</span></Label>
+						<Label for="test_code">{m["labResults_loincCode"]()} <span class="text-xs text-muted-foreground">(e.g. 718-7)</span></Label>
 						<Input id="test_code" name="test_code" required placeholder="718-7" />
 					</div>
 					<div class="space-y-1">
-						<Label for="test_name_original">Test name</Label>
-						<Input id="test_name_original" name="test_name_original" placeholder="e.g. Hemoglobin" />
+						<Label for="test_name_original">{m["labResults_testName"]()}</Label>
+						<Input id="test_name_original" name="test_name_original" placeholder={m["labResults_testNamePlaceholder"]()} />
 					</div>
 					<div class="space-y-1">
-						<Label for="lab">Lab</Label>
-						<Input id="lab" name="lab" placeholder="e.g. LabCorp" />
+						<Label for="lab">{m["labResults_lab"]()}</Label>
+						<Input id="lab" name="lab" placeholder={m["labResults_labPlaceholder"]()} />
 					</div>
 					<div class="space-y-1">
-						<Label for="value_num">Value</Label>
+						<Label for="value_num">{m["labResults_value"]()}</Label>
 						<Input id="value_num" name="value_num" type="number" step="any" />
 					</div>
 					<div class="space-y-1">
-						<Label for="unit_original">Unit</Label>
-						<Input id="unit_original" name="unit_original" placeholder="e.g. g/dL" />
+						<Label for="unit_original">{m["labResults_unit"]()}</Label>
+						<Input id="unit_original" name="unit_original" placeholder={m["labResults_unitPlaceholder"]()} />
 					</div>
 					<div class="space-y-1">
-						<Label>Flag</Label>
+						<Label>{m["labResults_flag"]()}</Label>
 						<input type="hidden" name="flag" value={selectedFlag} />
 						<Select type="single" value={selectedFlag} onValueChange={(v) => (selectedFlag = v)}>
-							<SelectTrigger>{selectedFlag || 'None'}</SelectTrigger>
+							<SelectTrigger>{selectedFlag || m["labResults_flagNone"]()}</SelectTrigger>
 							<SelectContent>
-								<SelectItem value="">None</SelectItem>
+								<SelectItem value="">{m["labResults_flagNone"]()}</SelectItem>
 								{#each flags as f (f)}
 									<SelectItem value={f}>{f}</SelectItem>
 								{/each}
@@ -117,7 +118,7 @@
 						</Select>
 					</div>
 					<div class="flex items-end">
-						<Button type="submit">Add</Button>
+						<Button type="submit">{m.common_add()}</Button>
 					</div>
 				</form>
 			</CardContent>
@@ -128,12 +129,12 @@
 		<Table>
 			<TableHeader>
 				<TableRow>
-					<TableHead>Date</TableHead>
-					<TableHead>Test</TableHead>
-					<TableHead>LOINC</TableHead>
-					<TableHead>Value</TableHead>
-					<TableHead>Flag</TableHead>
-					<TableHead>Lab</TableHead>
+					<TableHead>{m["labResults_colDate"]()}</TableHead>
+					<TableHead>{m["labResults_colTest"]()}</TableHead>
+					<TableHead>{m["labResults_colLoinc"]()}</TableHead>
+					<TableHead>{m["labResults_colValue"]()}</TableHead>
+					<TableHead>{m["labResults_colFlag"]()}</TableHead>
+					<TableHead>{m["labResults_colLab"]()}</TableHead>
 				</TableRow>
 			</TableHeader>
 			<TableBody>
@@ -165,7 +166,7 @@
 				{:else}
 					<TableRow>
 						<TableCell colspan={6} class="text-center text-muted-foreground py-8">
-							No lab results found.
+							{m["labResults_noResults"]()}
 						</TableCell>
 					</TableRow>
 				{/each}