refactor: migrate all Svelte components from Svelte 4 to Svelte 5 runes

- Replace `export let` with `$props()` and `$bindable()` across all components
- Replace `$:` reactive statements with `$derived()` and `$effect()`
- Replace `createEventDispatcher` with callback props (e.g. `onchange`)
- Replace `on:event` directives with inline event handlers (`onclick`, `oninput`, etc.)
- Replace `<slot />` with `{@render children()}` in layout
- Use `untrack()` for SSR-safe $state initialization from reactive props
- Replace `blur` + `setTimeout` anti-pattern in TagInput with `clickOutside` action
- Fix `page` store usage in layout to use `$app/state` directly
- 0 errors, 0 warnings after svelte-check

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

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

@@ -1,10 +1,10 @@
 <script lang="ts">
 import { goto } from '$app/navigation';
-export let data;
 
-let searchTimeout: any;
+let { data } = $props();
+
+let searchTimeout: ReturnType<typeof setTimeout>;
 
-// Live-Suche (Debounce)
 function handleSearch(e: Event) {
 	const value = (e.target as HTMLInputElement).value;
 	clearTimeout(searchTimeout);
@@ -49,7 +49,7 @@ function handleSearch(e: Event) {
 					type="text"
 					placeholder="Namen suchen..."
 					value={data.q || ''}
-					on:input={handleSearch}
+					oninput={handleSearch}
 					class="block w-full rounded-sm border border-gray-300 bg-white py-2.5 pr-10 pl-4 font-sans text-sm text-brand-navy placeholder-gray-400 shadow-sm focus:border-brand-navy focus:ring-1 focus:ring-brand-navy focus:outline-none"
 				/>
 				<div