Implement Time Machine xattr support (Phase 4.1 complete)

vendor/smb-server/src/handlers/tree_connect.rs

@@ -94,6 +94,31 @@ pub async fn handle(
         Access::Read => FILE_GENERIC_READ | FILE_GENERIC_EXECUTE,
         Access::ReadWrite => FILE_ALL_ACCESS,
     };
+    
+    // Time Machine: set xattr on share root directory
+    if share.time_machine {
+        use crate::path::SmbPath;
+        let root_path = SmbPath::root();
+        
+        // Generate UUID for this Time Machine backup
+        let uuid = uuid::Uuid::new_v4();
+        let uuid_bytes = uuid.as_bytes();
+        
+        // Set com.apple.TimeMachine.SupportedFilesStoreUUID
+        share.backend.set_xattr(&root_path, "com.apple.TimeMachine.SupportedFilesStoreUUID", uuid_bytes).await.ok();
+        
+        // Set com.apple.TimeMachine.SupportsThisDevice (1 = true)
+        share.backend.set_xattr(&root_path, "com.apple.TimeMachine.SupportsThisDevice", &[1]).await.ok();
+        
+        // Set max_size if specified
+        if let Some(max_size) = share.time_machine_max_size {
+            let max_size_bytes = max_size.to_le_bytes();
+            share.backend.set_xattr(&root_path, "com.apple.TimeMachine.MaxSize", &max_size_bytes).await.ok();
+        }
+        
+        tracing::info!(share = %share.name, uuid = %uuid, "Time Machine enabled");
+    }
+    
     let resp = TreeConnectResponse {
         structure_size: 16,
         share_type: if share.is_ipc {