v0.5.2 - No-clone quick install

Promotes no-clone setup into the first visible README section. Adds docs/no-clone-quick-install.md with a copy-paste AI-agent handoff prompt plus one-paste PowerShell and Bash adapter installers. Updates localized READMEs and getting-started guidance so new users can start without cloning the repository. Expands validation to require the no-clone quick install path.