feat(frontend): rename route to /korrespondenz, update i18n, regen API types

Moves conversations/ to korrespondenz/, updates all internal links,
renames nav label and page heading to Korrespondenz across de/en/es,
and adds all new i18n keys for the redesigned strip and log.

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

frontend/src/routes/korrespondenz/+page.svelte

@@ -0,0 +1,104 @@
+<script lang="ts">
+import { goto } from '$app/navigation';
+import { untrack } from 'svelte';
+import { SvelteURLSearchParams } from 'svelte/reactivity';
+import { m } from '$lib/paraglide/messages.js';
+import ConversationFilterBar from './ConversationFilterBar.svelte';
+import ConversationTimeline from './ConversationTimeline.svelte';
+
+let { data } = $props();
+
+let senderId = $state(untrack(() => data.filters.senderId));
+let receiverId = $state(untrack(() => data.filters.receiverId));
+let fromDate = $state(untrack(() => data.filters.from));
+let toDate = $state(untrack(() => data.filters.to));
+let sortDir = $state(untrack(() => data.filters.dir));
+
+// Sync with server data after navigation
+$effect(() => {
+	senderId = data.filters.senderId;
+	receiverId = data.filters.receiverId;
+	fromDate = data.filters.from;
+	toDate = data.filters.to;
+	sortDir = data.filters.dir;
+});
+
+function applyFilters() {
+	const params = new SvelteURLSearchParams();
+	if (senderId) params.set('senderId', senderId);
+	if (receiverId) params.set('receiverId', receiverId);
+	if (fromDate) params.set('from', fromDate);
+	if (toDate) params.set('to', toDate);
+	params.set('dir', sortDir);
+	goto(`/korrespondenz?${params.toString()}`, { keepFocus: true });
+}
+
+function toggleSort() {
+	sortDir = sortDir === 'DESC' ? 'ASC' : 'DESC';
+	applyFilters();
+}
+
+function swapPersons() {
+	const tmp = senderId;
+	senderId = receiverId;
+	receiverId = tmp;
+	applyFilters();
+}
+</script>
+
+<div class="mx-auto max-w-5xl px-4 py-10">
+	<!-- Page Header -->
+	<div class="mb-8 border-b border-ink/10 pb-4">
+		<h1 class="font-serif text-3xl font-medium text-ink">{m.conv_heading()}</h1>
+		<p class="mt-2 font-sans text-sm text-ink-2">
+			{m.conv_subtitle()}
+		</p>
+	</div>
+
+	<ConversationFilterBar
+		bind:senderId={senderId}
+		bind:receiverId={receiverId}
+		bind:fromDate={fromDate}
+		bind:toDate={toDate}
+		bind:sortDir={sortDir}
+		initialSenderName={data.initialValues.senderName}
+		initialReceiverName={data.initialValues.receiverName}
+		onapplyFilters={applyFilters}
+		ontoggleSort={toggleSort}
+		onswapPersons={swapPersons}
+	/>
+
+	<!-- RESULTS LIST SECTION -->
+	{#if !senderId || !receiverId}
+		<div
+			class="flex flex-col items-center justify-center rounded-sm border border-dashed border-line bg-surface py-24 text-center"
+		>
+			<div class="mb-4 rounded-full bg-muted p-4 text-ink">
+				<svg class="h-8 w-8" fill="none" stroke="currentColor" viewBox="0 0 24 24"
+					><path
+						stroke-linecap="round"
+						stroke-linejoin="round"
+						stroke-width="2"
+						d="M17 20h5v-2a3 3 0 00-5.356-1.857M17 20H7m10 0v-2c0-.656-.126-1.283-.356-1.857M7 20H2v-2a3 3 0 015.356-1.857M7 20v-2c0-.656.126-1.283.356-1.857m0 0a5.002 5.002 0 019.288 0M15 7a3 3 0 11-6 0 3 3 0 016 0zm6 3a2 2 0 11-4 0 2 2 0 014 0zM7 10a2 2 0 11-4 0 2 2 0 014 0z"
+					/></svg
+				>
+			</div>
+			<p class="font-serif text-lg text-ink">{m.conv_empty_heading()}</p>
+			<p class="mt-1 font-sans text-sm text-ink-2">{m.conv_empty_text()}</p>
+		</div>
+	{:else if data.documents.length === 0}
+		<div
+			class="flex flex-col items-center justify-center rounded-sm border border-line bg-surface py-24 text-center shadow-sm"
+		>
+			<p class="font-serif text-ink">{m.conv_no_results_heading()}</p>
+			<p class="mt-2 text-sm text-ink-3">{m.conv_no_results_text()}</p>
+		</div>
+	{:else}
+		<ConversationTimeline
+			documents={data.documents}
+			senderId={senderId}
+			receiverId={receiverId}
+			canWrite={data.canWrite}
+		/>
+	{/if}
+</div>