1. architecture.md: Fixed diagram to show 'studio' instead of 'g3-console'
(the crate was renamed during development)
2. analysis/memory.md: Removed reference to non-existent machine_ui_writer.rs
3. theme.rs: Clarified that 'retro' is a theme option (the default theme),
not a separate TUI mode. No --retro CLI flag exists.
81ea149369