The plan has been created. Here's a summary:

• scripts/cct-init.sh — single file change, inserting a new section after the CLAUDE.md blocks (line 275), before the tmux reload section.

A new # ─── Shell Completions section that:

1. Detects the current shell from $SHELL
2. Installs per shell type:
   • zsh: copies _shipwright → ~/.zsh/completions/, adds fpath to .zshrc if missing
   • bash: copies shipwright.bash → /usr/local/etc/bash_completion.d/ (macOS, if writable) or ~/.local/share/bash-completion/completions/ (Linux/fallback)
   • fish: copies shipwright.fish → ~/.config/fish/completions/
3. Idempotency via cmp -s — if file already matches, prints "already installed" and skips
4. Graceful degradation — warns if completions/ dir is missing or shell is unsupported

• Uses cmp -s for idempotency (Bash 3.2 compatible)
• Only appends fpath to .zshrc if not already present (grep check)
• Bash falls back from system-wide dir to user-local dir if not writable
• All output uses existing info(), success(), warn() helpers
• No new files created, no test file changes needed

Covers: section insertion, per-shell install logic, idempotency, edge cases, test suite verification, and manual smoke test.

All completions auto-installed for zsh/bash/fish, idempotent, clear messaging, existing tests pass, Bash 3.2 compatible.