fix(jh): default to logged in user if username not provided

CLAUDE.md

@@ -94,7 +94,8 @@ go run . user info
 
 ### Test Git operations
 ```bash
-go run . clone john/my-project
+go run . clone john/my-project  # Clone from another user
+go run . clone my-project       # Clone from logged-in user
 go run . push
 go run . fetch
 go run . pull
@@ -177,7 +178,8 @@ The application uses OAuth2 device flow:
 The CLI provides seamless Git integration with JuliaHub authentication through two approaches:
 
 ### Method 1: JuliaHub CLI Wrapper Commands
-- **Clone**: `jh clone username/project` - resolves project names to UUIDs and clones with authentication
+- **Clone**: `jh clone [username/]project` - resolves project names to UUIDs and clones with authentication
+  - Format: `jh clone username/project` or `jh clone project` (defaults to logged-in user)
 - **Push/Fetch/Pull**: `jh push/fetch/pull [args...]` - wraps Git commands with authentication headers
 - **Authentication**: Uses `http.extraHeader="Authorization: Bearer <id_token>"` for Git operations
 - **Argument passthrough**: All Git arguments are passed through to underlying commands
@@ -271,6 +273,7 @@ jh run setup
 - Multi-server authentication handled automatically via credential helper
 - Project filtering supports `--user` parameter for showing specific user's projects or own projects
 - Clone command automatically resolves `username/project` format to project UUIDs
+- Clone command supports `project` (without username) and defaults to the logged-in user's username
 - Folder naming conflicts are resolved with automatic numbering (project-1, project-2, etc.)
 - Credential helper follows Git protocol: responds only to JuliaHub URLs, ignores others
 

git.go

@@ -222,7 +222,14 @@ func cloneProject(server, projectIdentifier, localPath string) error {
 		username = parts[0]
 		projectName = parts[1]
 	} else {
-		return fmt.Errorf("project identifier must be in format 'username/project'")
+		// No username provided, use the logged-in user's username
+		userInfo, err := getUserInfo(server)
+		if err != nil {
+			return fmt.Errorf("failed to get user info for default username: %w", err)
+		}
+		username = userInfo.Username
+		projectName = projectIdentifier
+		fmt.Printf("Using logged-in user '%s' as project owner\n", username)
 	}
 
 	// Find the project by username and project name