Connect GitHub from the human Setup Guide
HOLD: depends on #26741 and #26770; native integration test, real before/after captures, and independent review remain pending.
The Setup Guide now has a Connect GitHub button. A click runs accounts.githubConnect, the same action as Settings > Accounts, which opens the existing GitHub App connection flow and shows its connection/recovery state in Accounts. Reading the guide does not start authentication. This PR adds no connection client or backend flow.
The existing setup TASKS manifest supplies the human step and button metadata, generated native defaults/docs, and agent advice using cmux accounts github-connect. The copy asks the person to review repositories and permissions, finish pending browser approval, and check the result before claiming a connection. It makes no live credential-validity or remote-machine configuration claims.
Request from the onboarding brief:
In Settings and onboarding: one Connect GitHub button that runs integration.connect, shows connected/not connected from integration.list, and offers a disconnect through revoke. Remove the "gh auth login first" text. Before/after screenshots. Do not wait on hb-acpmux for this. Stop when it is merged.
This is stacked on the human Setup Guide PR #26741. #26770 (67e4654ac936ad9e8da764145a31ae3c052b6c72) owns the shared accounts.githubConnect action, Settings connection state and revoke flow. The guide delegates to that action; its regression requires the actual catalog descriptor, then checks that opening the page invokes nothing and clicking the button reaches the registry as a user gesture. No new permissions, login executor, polling, timers or default changes.
Design: retain the quiet native reading layout from the Claude first-run reference, cmux colours and glass, and one control-sized button below the relevant instruction. The existing compact/balanced/roomy gallery renders the added button in light/dark; narrow-width checks cover every row.
Validation so far:
- Generated Swift/JSON/docs parity: 2 Python checks passed.
- SetupGuide catalog: all 21 supported locales; scoped validator passed.
- No-SwiftUI, native selector scan, embedded-input coverage, whitespace and pre-push checks passed.
- Focused Linux setup and generation tests passed in run40652545746 at ea366fd57535d120ae69bec1b6c35754ca787b3a. The follow-up is now rebased onto the parent Cloud-copy correction at4f07b631befb797d52c5aab4b965fda807cb144d; its GitHub action/manifest implementation is unchanged. Parent run40653151720 checks the corrected Cloud instructions.
- Native test/capture work waits for dependencies and the controller recovery. No provider success is claimed from fixtures.
Agent session: agent session