feat: wire Cloud card on Home to real FileBrowser data

Add getUsage() method to filebrowser-client that fetches root directory
and returns total size and folder count. Home.vue Cloud card now shows
real storage used and folder count instead of hardcoded values.

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

neode-ui/src/api/filebrowser-client.ts

@@ -104,6 +104,23 @@ class FileBrowserClient {
     if (!res.ok) throw new Error(`Delete failed: ${res.status}`)
   }
 
+  async getUsage(): Promise<{ totalSize: number; folderCount: number; fileCount: number }> {
+    if (!this.isAuthenticated) {
+      const ok = await this.login()
+      if (!ok) return { totalSize: 0, folderCount: 0, fileCount: 0 }
+    }
+    const res = await fetch(`${this.baseUrl}/api/resources/`, {
+      headers: this.headers(),
+    })
+    if (!res.ok) return { totalSize: 0, folderCount: 0, fileCount: 0 }
+    const data: FileBrowserListResponse = await res.json()
+    const items = data.items || []
+    const folderCount = items.filter(i => i.isDir).length
+    const fileCount = items.filter(i => !i.isDir).length
+    const totalSize = items.reduce((sum, i) => sum + (i.size || 0), 0)
+    return { totalSize, folderCount, fileCount }
+  }
+
   async rename(oldPath: string, newName: string): Promise<void> {
     const safePath = oldPath.startsWith('/') ? oldPath : `/${oldPath}`
     const dir = safePath.substring(0, safePath.lastIndexOf('/') + 1)