feat: add option to create projects and components in same dir

[agviegas]

• Allows thatopen create . to scaffold into the current directory instead of creating a new subdirectory
• Derives the package name from the current folder name (via basename(cwd)) when using .
• Skips the "directory already exists" check when targeting the current directory
• Skips creating the target directory (only creates src/ with recursive: true)
• Adjusts the "Next steps" output — doesn't print cd ., shows "Project ready!" instead of "Created ./."
• Updates the help text to mention "." as an option for the project-name argument
• Also includes an unrelated change in src/built-in/index.ts (8 lines added)