One easy install from all three doors: website app, marketplace plugin, GitHub repo

Installing Computer Use should be smooth from all three doors, and today each door tells a different story:

1. Website Mac app download (codewhale.net/computer-use) — the signed .app with bundled helper; needs Accessibility + Screen Recording grants with a guided path when missing.
2. Marketplace plugin (codewhale-plugin-marketplace plugins/computer-use) — install/enable/trust flow inside CodeWhale; must land on the same helper + grants without a second ceremony.
3. GitHub repo (Hmbown/codewhale-cu-plugin) — source checkout: npm test, build:app/install:app, MCP stdio wiring for other hosts (muse bundle pattern), dev prerequisites.

Work: audit what each surface says and does today; converge on one install narrative (same version truth, same grant troubleshooting, same verify step — e.g. request_access receipt); fix the repo-side surfaces in this project (README quickstart, DISTRIBUTION/RELEASE_CHECKLIST, marketplace install copy); prepare website source changes for human-gated deploy (gh workflow run web.yml — never deploy from this work).

Acceptance sketch: a clean-machine user coming through any one door reaches a working background TextEdit observe-act-verify loop following only that door's instructions, with every failure naming the missing piece (app vs grant vs host), and all three doors agree on the current version and the verify receipt.