mappings.lua belongs in the nvchad repo — putting it in dotfiles/nvim/ conflicts
with the nvchad git-tracked copy on every sync. Feature modules (rename_term,
telescope_tasks) stay in setup_env as intended. Also removes the misplaced
symlink block in install_nvchad.sh that ran before backup/clone.
Co-Authored-By: Claude Sonnet 4.6 (1M context) <noreply@anthropic.com>