docs: update README to reflect arty-based setup and removed Ansible playbook

- Replace Ansible provisioning workflow with arty installation scripts
- Update arty.yml configuration to show simplified structure
- Add HiDrive integration documentation for .zlogin
- Update environment structure to show version managers and symbolic links
- Remove references to playbook.yml and environment-based repo management
- Add documentation for new installation scripts (debian, rust, zed, claude, etc.)
- Clean up .zshenv and remove .last_pwd tracking file

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

.zshenv

@@ -1,2 +0,0 @@
-
-. "$HOME/.cargo/env"