feat(korrespondenz): address PR #164 review – blockers and suggestions

Blockers (14):
- B1: fix senderName/receiverName to use $derived instead of $state + sync $effect
- B2: migrate all korrespondenz components from messages-extra shim to paraglide m.*
- B3: i18n CorrespondenzEmptyState (heading, subtext, search placeholder)
- B4: add response.ok checks to admin layout server load
- B5: add response.ok checks to korrespondenz page server load
- B6: add page.server.spec.ts with 5 test suites for korrespondenz load function
- B7: add axe-core accessibility checks to all e2e korrespondenz tests
- B8: add Testcontainers JPQL tests for findSinglePersonCorrespondence (DISTINCT + sender)
- B9: hide auth reset-token endpoint from OpenAPI spec; remove from generated api.ts
- B11: replace amber hardcoded hex colors in SinglePersonHintBar with brand tokens
- B12: replace clipboard emoji with Heroicons SVG in SinglePersonHintBar
- B13: create DateInput component (German dd.mm.yyyy); use it in CorrespondenzFilterControls
- B14: add Paraglide compile step to CI workflow before lint/test

Suggestions (11):
- S1: make CorrespondentSuggestionsDropdown a pure display component; lift fetch to PersonBar
- S2: fix leftover messages-extra import in ConversationTimeline; use brand tokens for status dots
- S3: add intent comment to EntityNav openFlyout behavior
- S4: rename canManageGroups → canManagePermissions throughout admin
- S6: remove domFlush helper from DateInput spec; use expect.poll instead
- S7: replace test.skip with throw new Error in bilateral e2e tests
- S8: add inverse aria-disabled test for filter strip
- S9: remove sm:min-h-0 from sort button to preserve 44px touch target
- S10: add title attributes to tablet trigger buttons in EntityNav
- S11: delete messages-extra.ts shim entirely

Also: fix admin pages revealing blank strip at bottom (-mb-6 on admin layout)

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

frontend/src/lib/components/DateInput.svelte

@@ -0,0 +1,75 @@
+<script lang="ts">
+import { isoToGerman, handleGermanDateInput, germanToIso } from '$lib/utils/date';
+import { m } from '$lib/paraglide/messages.js';
+
+interface Props {
+	value?: string;
+	errorMessage?: string | null;
+	name?: string;
+	id?: string;
+	placeholder?: string;
+	class?: string;
+	onchange?: () => void;
+}
+
+let {
+	value = $bindable(''),
+	errorMessage = $bindable<string | null>(null),
+	name,
+	id,
+	placeholder,
+	class: className = '',
+	onchange
+}: Props = $props();
+
+let display = $state(isoToGerman(value ?? ''));
+
+function handleInput(e: Event) {
+	const result = handleGermanDateInput(e);
+	display = result.display;
+
+	if (result.display === '') {
+		value = '';
+		errorMessage = null;
+		return;
+	}
+
+	if (result.display.length < 10) {
+		value = '';
+		errorMessage = m.form_date_error();
+		return;
+	}
+
+	const iso = germanToIso(result.display);
+	if (!iso) {
+		value = '';
+		errorMessage = m.form_date_error();
+		return;
+	}
+
+	const [, mo, d] = iso.split('-').map(Number);
+	if (mo < 1 || mo > 12 || d < 1 || d > 31) {
+		value = '';
+		errorMessage = m.form_date_error();
+		return;
+	}
+
+	value = iso;
+	errorMessage = null;
+	onchange?.();
+}
+</script>
+
+<input
+	type="text"
+	inputmode="numeric"
+	maxlength="10"
+	id={id}
+	value={display}
+	placeholder={placeholder ?? m.form_placeholder_date()}
+	oninput={handleInput}
+	class={className}
+/>
+{#if name}
+	<input type="hidden" name={name} value={value} />
+{/if}

frontend/src/lib/components/DateInput.svelte.spec.ts

@@ -3,9 +3,6 @@ import { cleanup, render } from 'vitest-browser-svelte';
 import { page } from 'vitest/browser';
 import DateInput from './DateInput.svelte';
 
-/** Wait one macrotask so Svelte can flush reactive DOM updates. */
-const domFlush = () => new Promise<void>((r) => setTimeout(r, 50));
-
 afterEach(() => cleanup());
 
 // ─── Rendering ────────────────────────────────────────────────────────────────
@@ -197,10 +194,9 @@ describe('DateInput – hidden input for form submission', () => {
 		render(DateInput, { name: 'documentDate', value: '' });
 		const input = page.getByRole('textbox');
 		await input.fill('20122024');
-		await domFlush();
 		const hidden = document.querySelector<HTMLInputElement>(
 			'input[type="hidden"][name="documentDate"]'
 		);
-		expect(hidden?.value).toBe('2024-12-20');
+		await expect.poll(() => hidden?.value).toBe('2024-12-20');
 	});
 });