Fix routing and optimize paths layout

- Fix double base path in tab navigation (router.push handles it)
- Use multi-column grid for files in shallow folders
- Show item counts always (not just on hover)
- Better use of horizontal space on desktop

src/app/os/layout.tsx

@@ -40,7 +40,7 @@ export default function OSDetailLayout({
 
   const handleTabChange = (tab: string) => {
     if (tab === "bin") return;
-    router.push(addBasePath(`/os/${tab}?os=${os}`));
+    router.push(`/os/${tab}?os=${os}`);
   };
 
   return (

src/components/filesystem.tsx

@@ -21,6 +21,39 @@ function countItems(item: TreeWithFullPath): number {
   return count;
 }
 
+function getMaxDepth(item: TreeWithFullPath, current = 0): number {
+  let max = current;
+  for (const value of Object.values(item)) {
+    if (typeof value !== "string") {
+      max = Math.max(max, getMaxDepth(value, current + 1));
+    }
+  }
+  return max;
+}
+
+function FileItem({
+  name,
+  fullPath,
+  os,
+}: {
+  name: string;
+  fullPath: string;
+  os: string;
+}) {
+  return (
+    <div className="flex items-center gap-2 py-1 px-1 hover:bg-accent rounded transition-colors">
+      <FileText className="h-4 w-4 shrink-0 text-muted-foreground" />
+      <Link
+        href={`/os/bin?path=${encodeURIComponent(fullPath)}&os=${os}`}
+        className="font-mono text-sm hover:underline text-muted-foreground hover:text-foreground truncate"
+        title={fullPath}
+      >
+        {name}
+      </Link>
+    </div>
+  );
+}
+
 function Tree({
   item,
   os,
@@ -32,35 +65,36 @@ function Tree({
   depth: number;
   expandAll: boolean;
 }) {
+  const entries = Object.entries(item);
+  const files = entries.filter(([, v]) => typeof v === "string");
+  const folders = entries.filter(([, v]) => typeof v !== "string");
+
   return (
     <ul className="space-y-0.5">
-      {Object.entries(item).map(([key, value]) => {
-        if (typeof value === "string") {
-          return (
-            <li key={value} className="flex items-center gap-2 py-1 pl-1">
-              <FileText className="h-4 w-4 shrink-0 text-muted-foreground" />
-              <Link
-                href={`/os/bin?path=${encodeURIComponent(value)}&os=${os}`}
-                className="font-mono text-sm hover:underline hover:text-foreground text-muted-foreground truncate"
-                title={value}
-              >
-                {key}
-              </Link>
-            </li>
-          );
-        } else {
-          return (
-            <TreeFolder
-              key={key}
-              name={key}
-              item={value}
-              os={os}
-              depth={depth}
-              expandAll={expandAll}
-            />
-          );
-        }
-      })}
+      {folders.map(([key, value]) => (
+        <TreeFolder
+          key={key}
+          name={key}
+          item={value as TreeWithFullPath}
+          os={os}
+          depth={depth}
+          expandAll={expandAll}
+        />
+      ))}
+      {files.length > 0 && (
+        <li>
+          <div className="grid grid-cols-1 md:grid-cols-2 xl:grid-cols-3 gap-x-4">
+            {files.map(([key, value]) => (
+              <FileItem
+                key={value as string}
+                name={key}
+                fullPath={value as string}
+                os={os}
+              />
+            ))}
+          </div>
+        </li>
+      )}
     </ul>
   );
 }
@@ -80,6 +114,8 @@ function TreeFolder({
 }) {
   const [open, setOpen] = useState(expandAll || depth < 1);
   const itemCount = countItems(item);
+  const maxDepth = getMaxDepth(item);
+  const isShallow = maxDepth === 0;
 
   return (
     <li>
@@ -92,13 +128,26 @@ function TreeFolder({
           )}
           <Folder className="h-4 w-4 shrink-0 text-muted-foreground" />
           <span className="font-mono text-sm truncate">{name}</span>
-          <span className="ml-auto text-xs text-muted-foreground opacity-0 group-hover:opacity-100 transition-opacity">
+          <span className="ml-2 text-xs text-muted-foreground">
             {itemCount}
           </span>
         </CollapsibleTrigger>
         <CollapsibleContent>
-          <div className="ml-4 pl-2 border-l border-border">
-            <Tree item={item} os={os} depth={depth + 1} expandAll={expandAll} />
+          <div className={isShallow ? "ml-6 mt-1" : "ml-4 pl-2 border-l border-border"}>
+            {isShallow ? (
+              <div className="grid grid-cols-1 md:grid-cols-2 xl:grid-cols-3 gap-x-4">
+                {Object.entries(item).map(([key, value]) => (
+                  <FileItem
+                    key={value as string}
+                    name={key}
+                    fullPath={value as string}
+                    os={os}
+                  />
+                ))}
+              </div>
+            ) : (
+              <Tree item={item} os={os} depth={depth + 1} expandAll={expandAll} />
+            )}
           </div>
         </CollapsibleContent>
       </Collapsible>