fix: skip model size comparison in diff check (Blender compression changes size)

Models are always re-pushed server-side since Draco compression changes
the file size, making client/remote size comparison unreliable.
Textures are still compared by size (not compressed, reliable).
Client-side diff now only flags models as 'new' if absent from remote,
and never as 'changed' (server handles the actual push decision).

components/UploadZone.tsx

@@ -44,33 +44,31 @@ async function checkFolderDiffs(
     const remoteFiles: { name: string; size: number }[] = data.files || []
     const remoteMap = new Map(remoteFiles.map((f) => [f.name.toLowerCase(), f.size]))
 
-    // Build local file list with sizes
-    const localFiles: { name: string; size: number }[] = []
-    localFiles.push({
-      name: folder.modelFile.name,
-      size: folder.modelFile.size,
-    })
-    for (const tex of folder.textures) {
-      localFiles.push({
-        name: tex.name,
-        size: tex.file.size,
-      })
-    }
-
     const diffs: FileDiff[] = []
     const localNames = new Set<string>()
 
-    for (const local of localFiles) {
-      const key = local.name.toLowerCase()
+    // Model: skip size comparison (compression changes the size).
+    // We only check if it exists on remote or not.
+    const modelKey = folder.modelFile.name.toLowerCase()
+    localNames.add(modelKey)
+    if (!remoteMap.has(modelKey)) {
+      diffs.push({ name: folder.modelFile.name, status: 'new' })
+    }
+    // If model exists on remote → don't add to diffs (we can't know if it changed)
+
+    // Textures: compare by size (not compressed, so size is reliable)
+    for (const tex of folder.textures) {
+      const key = tex.name.toLowerCase()
       localNames.add(key)
       const remoteSize = remoteMap.get(key)
       if (remoteSize === undefined) {
-        diffs.push({ name: local.name, status: 'new' })
-      } else if (remoteSize !== local.size) {
-        diffs.push({ name: local.name, status: 'changed' })
+        diffs.push({ name: tex.name, status: 'new' })
+      } else if (remoteSize !== tex.file.size) {
+        diffs.push({ name: tex.name, status: 'changed' })
       }
     }
 
+    // Files on remote but not in local → deleted
     for (const [name] of remoteMap) {
       if (!localNames.has(name)) {
         diffs.push({ name, status: 'deleted' })