Add one-shot ./ide --bootstrap for fresh-machine setup

[kyleve]

What

Make ./ide --bootstrap (alias --setup) the single command a new Mac runs to get from a fresh clone to a generated project. It:

1. Verifies Xcode — a full Xcode.app (not just the Command Line Tools) that's selected and runnable; otherwise it prints the exact xcode-select / runFirstLaunch / license accept steps and exits. It does not auto-install Xcode (large, interactive App Store download).
2. Installs mise via its official installer if missing — self-contained, so Homebrew is no longer a prerequisite — and idempotently adds mise activate to your shell rc (zsh/bash).
3. Installs the pinned tools (mise install): Tuist, SwiftFormat, and now Ruby.
4. Falls through to the normal flow — Git hooks, sync-agents --install, tuist generate.

It composes with the existing flags, so ./ide --bootstrap -i --team-id ABCDE12345 is the true one-shot. Plain ./ide stays the fast path but now fails fast when mise isn't found, pointing at --bootstrap.

Ruby pin

sync-agents previously relied on Apple's deprecated system Ruby. This pins Ruby 3.4.10 in .mise.toml and routes sync-agents through mise exec from both ./ide and the pre-commit hook so the pinned Ruby is used regardless of shell activation.

We use mise's precompiled Ruby (ruby.compile = false): building from source with ruby-build failed on a clean Mac (the psych extension couldn't configure against libyaml), which would break the one-shot. Precompiled installs in ~30s with no toolchain and becomes mise's default in 2026.8.0.

Resolving mise without shell activation

Right after ./ide --bootstrap, mise lives at ~/.local/bin/mise but isn't on PATH until a new shell picks up activation. Both ./ide and the pre-commit hook shell out to mise, so a commit in that window would otherwise fail with mise: command not found. Two things address this:

• A shared find_mise (PATH -> official-installer ~/.local/bin -> Homebrew -> /usr/local) resolves the binary directly, and the hook installs a small mise() function shim so its existing mise exec ... call sites work regardless of PATH. Both surfaces guard with a clear "run ./ide --bootstrap" message when mise genuinely can't be found.
• On a fresh install, bootstrap idempotently appends mise activate to the user's shell rc (zsh -> ~/.zshrc, bash -> ~/.bashrc; a manual pointer for other shells) so new interactive shells have mise + tools on PATH. This is convenience only — nothing depends on it thanks to find_mise.

Verified locally (macOS, Xcode 27 beta, arm64)

• Full ./ide --bootstrap --no-open runs clean end-to-end (tools installed, sync-agents ran, tuist generate --no-open succeeded).
• Pinned Ruby 3.4.10 loads psych/yaml/json; sync-agents runs under it via mise exec.
• find_mise resolves via the ~/.local/bin fallback with mise off PATH, and the mise() shim delegates correctly.
• rc activation is idempotent (no duplicate line on re-run) and prints a manual note for non-zsh/bash shells.
• Fast-path guard fires: plain ./ide with no resolvable mise prints the run ./ide --bootstrap first error and exits non-zero.

Docs

README.md (Getting started leads with ./ide --bootstrap; Homebrew is now an optional alternative) and AGENTS.md (Ruby row in the build-system table + bootstrap note). Generated CLAUDE.md regenerated via sync-agents.