fix: sync reactive state with data prop using \$effect

Replaces bare \$state(data.x) initialisers (which only capture the
initial value) with \$state + \$effect pairs so that state stays in sync
whenever page data is invalidated or the URL changes. Affects all list
pages (searchValue) and all edit/detail pages (form fields).

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

packages/frontend/src/routes/admin/articles/+page.svelte

@@ -21,6 +21,7 @@
   let deleteOpen = $state(false);
   let deleting = $state(false);
   let searchValue = $state(data.search ?? "");
+  $effect(() => { searchValue = data.search ?? ""; });
   let searchTimeout: ReturnType<typeof setTimeout>;
 
   function debounceSearch(value: string) {

packages/frontend/src/routes/admin/articles/[id]/+page.svelte

@@ -28,6 +28,20 @@
   );
   let imageId = $state<string | null>(data.article.image ?? null);
   let authorId = $state(data.article.author?.id ?? "");
+  $effect(() => {
+    title = data.article.title;
+    slug = data.article.slug;
+    excerpt = data.article.excerpt ?? "";
+    content = data.article.content ?? "";
+    category = data.article.category ?? "";
+    tags = data.article.tags ?? [];
+    featured = data.article.featured ?? false;
+    publishDate = data.article.publish_date
+      ? new Date(data.article.publish_date).toISOString().slice(0, 16)
+      : "";
+    imageId = data.article.image ?? null;
+    authorId = data.article.author?.id ?? "";
+  });
   let selectedAuthor = $derived(data.authors.find((a) => a.id === authorId) ?? null);
   let saving = $state(false);
   let editorTab = $state<"write" | "preview">("write");

packages/frontend/src/routes/admin/comments/+page.svelte

@@ -18,6 +18,7 @@
   let deleteOpen = $state(false);
   let deleting = $state(false);
   let searchValue = $state(data.search ?? "");
+  $effect(() => { searchValue = data.search ?? ""; });
   let searchTimeout: ReturnType<typeof setTimeout>;
 
   function debounceSearch(value: string) {

packages/frontend/src/routes/admin/recordings/+page.svelte

@@ -19,6 +19,7 @@
   let deleteOpen = $state(false);
   let deleting = $state(false);
   let searchValue = $state(data.search ?? "");
+  $effect(() => { searchValue = data.search ?? ""; });
   let searchTimeout: ReturnType<typeof setTimeout>;
 
   function debounceSearch(value: string) {

packages/frontend/src/routes/admin/users/+page.svelte

@@ -16,6 +16,7 @@
   const { data } = $props();
 
   let searchValue = $state(data.search ?? "");
+  $effect(() => { searchValue = data.search ?? ""; });
   let searchTimeout: ReturnType<typeof setTimeout>;
   let deleteTarget: User | null = $state(null);
   let deleteOpen = $state(false);

packages/frontend/src/routes/admin/users/[id]/+page.svelte

@@ -24,6 +24,15 @@
   let photoId = $state<string | null>(data.user.photo ?? null);
   let isAdmin = $state(data.user.is_admin ?? false);
   let saving = $state(false);
+  $effect(() => {
+    firstName = data.user.first_name ?? "";
+    lastName = data.user.last_name ?? "";
+    artistName = data.user.artist_name ?? "";
+    avatarId = data.user.avatar ?? null;
+    bannerId = data.user.banner ?? null;
+    photoId = data.user.photo ?? null;
+    isAdmin = data.user.is_admin ?? false;
+  });
 
   async function handleAvatarUpload(files: File[]) {
     const file = files[0];

packages/frontend/src/routes/admin/videos/+page.svelte

@@ -18,6 +18,7 @@
   let deleteOpen = $state(false);
   let deleting = $state(false);
   let searchValue = $state(data.search ?? "");
+  $effect(() => { searchValue = data.search ?? ""; });
   let searchTimeout: ReturnType<typeof setTimeout>;
 
   function debounceSearch(value: string) {

packages/frontend/src/routes/admin/videos/[id]/+page.svelte

@@ -29,6 +29,20 @@
   let selectedModelIds = $state<string[]>(
     data.video.models?.map((m: { id: string }) => m.id) ?? [],
   );
+  $effect(() => {
+    title = data.video.title;
+    slug = data.video.slug;
+    description = data.video.description ?? "";
+    tags = data.video.tags ?? [];
+    premium = data.video.premium ?? false;
+    featured = data.video.featured ?? false;
+    uploadDate = data.video.upload_date
+      ? new Date(data.video.upload_date).toISOString().slice(0, 16)
+      : "";
+    imageId = data.video.image ?? null;
+    movieId = data.video.movie ?? null;
+    selectedModelIds = data.video.models?.map((m: { id: string }) => m.id) ?? [];
+  });
   let saving = $state(false);
 
   async function handleImageUpload(files: File[]) {