fix: image transforms via Sharp, model photos crash, video duration

- Backend: add Sharp image transform endpoint (/assets/:id?transform=X)
  with presets: mini(64), thumbnail(200), preview(480), medium(960), banner(1280)
  Transformed images are cached as webp next to originals
- Frontend: fix model photos crash (p.directus_files_id → p)
- Frontend: fix model banner URL (data.model.banner.id → data.model.banner)
- Frontend: fix video duration display (video.movie.duration → video.movie_file?.duration)
  across models/[slug], videos, videos/[slug], and home pages

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

packages/frontend/src/routes/models/[slug]/+page.svelte

@@ -22,9 +22,9 @@ const { data } = $props();
 
 let images = $derived(
 	data.model.photos.map((p) => ({
-		...p.directus_files_id,
-		url: getAssetUrl(p.directus_files_id.id),
-		thumbnail: getAssetUrl(p.directus_files_id.id, "thumbnail"),
+		...p,
+		url: getAssetUrl(p.id),
+		thumbnail: getAssetUrl(p.id, "thumbnail"),
 	})),
 );
 
@@ -52,7 +52,7 @@ let totalPlays = $derived(
   <div class="relative h-64 md:h-80 overflow-hidden bg-gradient-to-br from-primary to-accent">
     {#if data.model.banner}
       <img
-        src={getAssetUrl(data.model.banner.id, "banner")}
+        src={getAssetUrl(data.model.banner, "banner")}
         alt={$_(data.model.artist_name)}
         class="w-full h-full object-cover"
       />
@@ -243,7 +243,7 @@ let totalPlays = $derived(
                 <div
                   class="absolute bottom-2 left-2 text-white text-sm font-medium"
                 >
-                  {formatVideoDuration(video.movie.duration)}
+                  {#if video.movie_file?.duration}{formatVideoDuration(video.movie_file.duration)}{/if}
                 </div>
                 <!-- <div
                   class="absolute top-2 right-2 bg-black/50 text-white text-xs px-2 py-1 rounded-full"