feat(structures): hero image header on structure detail page

When the structure type has an image, render it as a full-bleed
cover behind the page header with vertical and horizontal gradient
overlays; text shifts to white for contrast. Headers without an
image keep the previous plain layout.

src/app/(frontend)/logistics/structures/[id]/page.tsx

@@ -72,6 +72,12 @@ export default async function StructureDetailPage({ params }: StructureDetailPag
     ? convertLexicalToPlaintext({ data: structureType.description })
     : null;
 
+  const image =
+    typeof structureType.image === "object" && structureType.image !== null
+      ? structureType.image
+      : null;
+  const imageUrl = image?.url ?? null;
+
   const totalValue = storedResources.reduce((sum, entry) => {
     const resource = entry.resource as Resource;
     if (!resource || typeof resource === "number") return sum;
@@ -80,22 +86,49 @@ export default async function StructureDetailPage({ params }: StructureDetailPag
 
   return (
     <div className="p-5 flex flex-col gap-6 max-w-7xl">
-      <div className="flex flex-col gap-3">
+      <header
+        className={`relative flex flex-col gap-3 overflow-hidden rounded-lg${
+          imageUrl ? " min-h-[280px] justify-between border border-border p-5" : ""
+        }`}
+      >
+        {imageUrl ? (
+          <>
+            <img
+              src={imageUrl}
+              alt={structure.name}
+              fetchPriority="high"
+              className="absolute inset-0 size-full object-cover"
+            />
+            <div className="absolute inset-0 bg-gradient-to-b from-black/50 via-black/40 to-background" />
+            <div className="absolute inset-0 bg-gradient-to-r from-black/30 via-transparent to-black/40" />
+          </>
+        ) : null}
+
         <Link
           href="/logistics"
-          className="text-sm text-muted-foreground hover:text-primary transition-colors flex items-center gap-1 w-fit"
+          className="relative z-10 text-sm text-muted-foreground hover:text-primary transition-colors flex items-center gap-1 w-fit"
         >
           <ArrowLeftIcon className="size-3" />
           Back to Structures
         </Link>
 
-        <div className="flex items-start justify-between gap-4">
+        <div className="relative z-10 flex items-start justify-between gap-4">
           <div className="flex flex-col gap-1">
             <div className="flex items-center gap-2">
-              <Building2Icon className="size-5 text-muted-foreground" />
+              <Building2Icon
-              <h1 className="text-lg font-semibold">{structure.name}</h1>
+                className={`size-5 ${imageUrl ? "text-white/80" : "text-muted-foreground"}`}
+              />
+              <h1
+                className={`text-lg font-semibold ${imageUrl ? "text-white drop-shadow-md" : ""}`}
+              >
+                {structure.name}
+              </h1>
             </div>
-            <div className="flex items-center gap-2 text-sm text-muted-foreground">
+            <div
+              className={`flex items-center gap-2 text-sm ${
+                imageUrl ? "text-white/70" : "text-muted-foreground"
+              }`}
+            >
               <span>{structureType.name}</span>
               <span>·</span>
               <span>{getCategoryLabel(structureType.category)}</span>
@@ -116,7 +149,7 @@ export default async function StructureDetailPage({ params }: StructureDetailPag
             {user && <ManageStorageButton structureId={structure.id} />}
           </div>
         </div>
-      </div>
+      </header>
 
       {description && <p className="text-sm text-muted-foreground">{description}</p>}