init: scaffold mac project + inventory + setup design

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

IDEA.md

@@ -0,0 +1,22 @@
+# IDEA.md — Project Idea
+
+## What is this?
+Ops home for Seth's new MacBook Pro (Sept 2026). Debloat it, make it feel like
+a Linux box to a Linux user, and tune it for Ableton Live 12 (native — the
+steel141/Wine route was abandoned 2026-09-14, see `~/bin/ableton/`).
+
+## Problem it solves
+Stock macOS is noisy (Siri, Spotlight indexing everything, iCloud nags,
+Photos/Music/News/TV auto-launch, animations, Dock junk) and the CLI is BSD
+userland with zsh — `ip a` doesn't exist. Want: quiet machine, GNU-flavoured
+shell, homelab reachability (SMB to tank, ssh aliases), and a DAW-first
+config (no Time Machine mid-set, no sleep/App Nap on Live, audio not
+tripped by notifications).
+
+## Constraints / preferences
+- Manage over SSH from steel141 (`ssh mac`, 192.168.0.94 LAN / Tailscale later)
+- Homebrew for everything installable; scripted + idempotent, not hand-clicked
+- `defaults write` changes are reversible — dump before changing (`.backup/`)
+- Don't fight SIP/Gatekeeper; disable *services*, don't rip out system apps
+- Ableton Suite Packs come with the license (in-app download); third-party
+  packs live at `/tank/Downloads/Software/Milkie/` via SMB from 192.168.0.173