fix(dashboard): i18n, a11y, security, and type-safety fixes from PR review

- Use @RequiredArgsConstructor in AuditLogQueryService; remove unused import
- Add 401/403 tests for /activity endpoint
- Add getPulseStats and findContributorsPerDocument integration tests
- Use m.pulse_headline/pulse_you in FamilyPulse; composite avatar keys
- Replace hover:text-accent with hover:text-ink in ActivityFeed (WCAG AA)
- Localise "Alle →" link with feed_show_all key + aria-label
- Gate DropZone behind {#if data.canWrite}
- Export DashboardResumeDTO, DashboardPulseDTO, ActivityFeedItemDTO from api.ts

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

frontend/src/lib/components/DashboardFamilyPulse.svelte

@@ -17,20 +17,20 @@ const { pulse }: Props = $props();
 
 		{#if pulse.pages > 0}
 			<h2 class="mt-1 font-serif text-[1.375rem] leading-snug text-ink">
-				Ihr habt <strong>{pulse.pages}</strong> Seiten bearbeitet.
+				{m.pulse_headline({ pages: pulse.pages })}
 			</h2>
 		{/if}
 
 		{#if pulse.yourPages > 0}
 			<p class="font-serif text-sm text-ink-2">
-				Du selbst hast {pulse.yourPages} davon bearbeitet.
+				{m.pulse_you({ pages: pulse.yourPages })}
 			</p>
 		{/if}
 
 		{#if pulse.contributors.length > 0}
 			<div class="mt-3 flex items-center gap-1">
 				<p class="mr-1 font-sans text-[11px] text-ink-3">{m.pulse_contributors()}</p>
-				{#each pulse.contributors as c (c.initials)}
+				{#each pulse.contributors as c (c.initials + c.color)}
 					<span
 						class="-ml-2 inline-flex h-7 w-7 items-center justify-center rounded-full font-sans text-[11px] font-bold text-white ring-2 ring-white first:ml-0"
 						style="background:{c.color}"

frontend/src/lib/generated/api.ts

@@ -4451,3 +4451,7 @@ export interface operations {
         };
     };
 }
+
+export type DashboardResumeDTO = components['schemas']['DashboardResumeDTO'];
+export type DashboardPulseDTO = components['schemas']['DashboardPulseDTO'];
+export type ActivityFeedItemDTO = components['schemas']['ActivityFeedItemDTO'];

frontend/src/routes/+page.svelte

@@ -151,7 +151,9 @@ const greetingText = $derived.by(() => {
 			<div class="flex flex-col gap-5 lg:sticky lg:top-[80px]">
 				<DashboardFamilyPulse pulse={data.pulse ?? null} />
 				<DashboardActivityFeed feed={data.activityFeed ?? []} />
-				<DropZone />
+				{#if data.canWrite}
+					<DropZone />
+				{/if}
 			</div>
 		</div>
 	{:else}