feat(lists): finish GitHub-backed list creation and add Refresh from GitHub #51

Summary

The macOS New List sheet shows GitHub source fields that do nothing:

App/Features/Lists/NewListSheetView.swift:85 — Section("GitHub source (optional)")
App/Features/Lists/NewListSheetView.swift:98 — Text("GitHub source fields will be sent in a future update.")

So a user can fill in a repo and get a plain local list. The web, meanwhile, has a full GitHub-backed list flow, and the client already ships the reading half (issue browser, create-issue-from-message, close/reopen, labels/assignees — G4 + the PR #24 route fixes).

The missing piece is creation and refresh.

What the web does (/help/lists)

Creating:

• Prerequisite: GitHub connected with the Issues scope. "If you already linked GitHub for sign-in, you may need to click Reconnect for GitHub Issues to grant access."
• On the GitHub-backed List tab, select a repository you have access to (a picker, not a free-text field)
• List title defaults to the repo name
• Optional parent list; optional Public toggle

Behaviour once created:

• Rows map to issues (title, body, labels, assignees, state). Adding a row creates an issue; editing a row updates it; deleting a row closes it.
• Schema is fixed — Edit changes only the parent list. "You cannot modify the issue fields … they are defined by GitHub."
• Refresh from GitHub pulls the latest issues (the list caches locally).
• Visibility is re-read from GitHub on every sync (create, manual refresh, scheduled sync).

Live facts (2026-09-07)

GET /api/github/repos        → 200 (test account is now GitHub-linked)  but the list is EMPTY
GET /api/github/orgs         → 200  []
GET /api/auth/github/status  → 200  {"configured":true,"clientId":"Ov23li9eXYK1i6psJW6G",
                                     "manageOrgAccessUrl":"https://github.com/settings/connections/applications/…"}

⚠️ The test account has no accessible repos, so the repo-picker payload and the githubSource-on-create request shape cannot be exercised end-to-end today. Before building, either grant the .env test account access to a repo, or capture the web app's own network calls for a create. Do not guess the create-time field names — work-consolidation.md P3-C records githubSource: { owner, repo, path, ref } as unconfirmed.

Also unconfirmed (P3-C)

The refresh metadata the UI needs — lastRefreshedAt, refreshStatus (idle|pending|failed), refreshError — is modelled in the domain as GitHubListSource but has never been seen on the wire. Probe before rendering a refresh state, or render only what is actually returned.

Division of labor

Kit

• Accept githubSource on POST /api/lists once the shape is confirmed.
• A repo-picker request builder over GET /api/github/repos (already present — confirm the populated shape against a repo-bearing account).
• Whatever route drives Refresh from GitHub; if none exists, file the backend ask rather than inventing one.
• Contract tests against a repo-bearing account.

Domain

• Extend list creation with a GitHub source, gated on the subscriber entitlement and on a GitHub identity with Issues scope.
• Model the fixed-schema rule so the schema editor refuses field edits on a GitHub-backed list and offers only the parent-list change.
• Refresh action + refresh state, only for the fields the probe confirms.

App

• Replace the dead GitHub section in NewListSheetView with a real repo picker populated from the account's repos, plus the title default.
• An inline Reconnect for GitHub Issues CTA when the identity lacks the scope — reuse the OAuth flow from the Integrations issue rather than building a second one.
• Refresh from GitHub in the list toolbar, with its state surfaced.
• Schema editor: parent-list-only mode for GitHub-backed lists, with an explanation rather than a silently disabled form.

Tests

• happy — pick a repo, create the list, rows arrive as issues
• invalid — GitHub not linked, or linked without Issues scope → the reconnect CTA, no create attempt
• upstream-failure — the repo list 500s → the picker shows an error and the local-list tab still works
• boundary — an account with zero accessible repos (today's test account) → an honest empty picker, not a spinner

Acceptance criteria

• No control in the New List sheet promises something "in a future update".
• A GitHub-backed list created on the Mac behaves the same as one created on the web.
• Full E2E gate green.

Notes

New finding from the 2026-09-07 parity sweep. Depends on P3-C (create-time and refresh shapes) and shares the OAuth scope-upgrade flow with the Integrations issue. Size M.