docs: macOS install, shell choice and zsh files

CLAUDE.md

@@ -21,6 +21,7 @@ vim/vimrc             vim config (pathogen, molokai, syntastic, NERDTree)
 vim/autoload/         pathogen loader (committed)
 vim/colors/           molokai colorscheme (committed)
 bash/bashrc-{linux,osx}          OS-detected bashrc
+zsh/{zshrc-osx,bchanot.zsh-theme}  macOS zsh option: oh-my-zsh zshrc + theme porting the bash prompt
 bin/{dt,dtach-router,claude-provider}   CLI scripts deployed to ~/.local/bin
 etc/profile.d/disk-usage-warning.sh     login-time low-disk warning → /etc/profile.d (Linux only)
 etc/tmpfiles.d/tmp.conf                 disk-backed /tmp cleanup rules (offer: /tmp on disk)
@@ -37,6 +38,12 @@ cloudpex/{cloudpex,install.sh,README.md} on-demand SMB mount helper → /usr/loc
 `/tmp` is a RAM-backed tmpfs on Ubuntu (50% of RAM): agent runs fill it, which is why
 install.sh offers to mask `tmp.mount`. Swap is not the fix (the cap and ENOSPC stay).
 
+macOS: install.sh swaps apt-get for Homebrew (colima for Docker, brew services for
+code-server/mariadb, `~/.bash_profile` → `~/.bashrc`), asks bash or zsh (`MACOS_SHELL`
+presets it; zsh = oh-my-zsh + `zsh/` files, bash = brew bash 5) and prints the Linux-only
+items it skipped. Keep `bashrc-osx` = `bashrc-linux` + macOS deltas only, and the zsh
+files in step with them (same env, aliases, prompt).
+
 `pymupdf`/`markdown_py` are NOT tracked — they are pipx entry-point shims,
 recreated by `pipx install PyMuPDF Markdown` in install.sh.
 `claude-provider` reads `$OPENROUTER_API_KEY` from the env — never hardcode it (the