Tracker: security and board automation on a GitHub App credential #2543

Goal

Put the repo's security and board automation on one GitHub App credential, so alerts, advisories and new issues reach board #28 without a maintainer running /issue-triage by hand, and so v2 code is scanned before the release PR rather than on it.

Why now

The v2.9.0 release showed every gap at once:

• CodeQL never scans v2/main. A high-severity ReDoS introduced this milestone (CLI error-envelope URL redaction uses a quadratic regex on server-controlled text (CodeQL, ReDoS) #2540) surfaced only on the milestone-merge PR, and held the release.
• Code-scanning alerts become no issues at all. Three high-severity alerts (Skip the dist/index.js bit #74–Improve Windows Support #76) are open and untracked.
• The Dependabot sweep files issues it cannot board, because the PROJECT_TOKEN it reads has never existed. The SDK watch and the monthly refresh never board by design, for the same reason.
• GHSA draft cards and nightly triage were both parked as blocked on the same credential, with no card of their own for the credential.

Structure

Everything that writes to the board waits on one prerequisite: the GitHub App. Two items need no credential and can start immediately.

The Sub-issues panel on this issue is the canonical list, in this order:

1. Create the GitHub App for board writes and security-alert reads, and store its credentials as org secrets #2544, the GitHub App. The long pole and human-gated (org admin), so it goes first and is requested now. Take every other admin decision to the same conversation (see below).
2. Scan v2/main with CodeQL: switch from default setup to a committed advanced-setup workflow #2545, CodeQL on v2/main. Needs no credential; runs in parallel with Create the GitHub App for board writes and security-alert reads, and store its credentials as org secrets #2544. Disabling default setup is a repo-admin act.
3. Move the Dependabot alert sweep from the nonexistent PROJECT_TOKEN to the GitHub App token #2547, the Dependabot sweep onto the App. The smallest consumer and the end-to-end proof that the App works; it sets the token-step pattern the rest copy.
4. GHSA draft cards: place on the board for the affected line, and include affected versions + reporter #2462, GHSA draft cards. Its docs half (skills, AGENTS.md) needs no credential and can start before Create the GitHub App for board writes and security-alert reads, and store its credentials as org secrets #2544 lands.
5. Board the SDK watch and monthly dependency-refresh issues with the GitHub App token #2548, boarding for the SDK watch and monthly refresh. Reuses Move the Dependabot alert sweep from the nonexistent PROJECT_TOKEN to the GitHub App token #2547's pattern.
6. Nightly security sweep: turn Dependabot and code-scanning (CodeQL) alerts into board-tracked issues #2542, the code-scanning sweep. Better after Scan v2/main with CodeQL: switch from default setup to a committed advanced-setup workflow #2545, so alerts exist on the v2/main ref instead of a file/line re-check.
7. Nightly triage: sweep unboarded issues onto the board and run the board audit #2463, nightly triage. The largest, and it needs a second credential decision (federation or a capped model key for third-party input).

#2546 (alerts #74–#76) is done.

Admin decisions to take in one pass

• Create and install the App with Create the GitHub App for board writes and security-alert reads, and store its credentials as org secrets #2544's permission list (and decide on the optional Administration: read).
• Disable CodeQL default setup when Scan v2/main with CodeQL: switch from default setup to a committed advanced-setup workflow #2545's workflow lands.
• Whether secret scanning is in Nightly security sweep: turn Dependabot and code-scanning (CodeQL) alerts into board-tracked issues #2542's scope (adds a read permission to the App).
• Nightly triage: sweep unboarded issues onto the board and run the board audit #2463's model credential: workload identity federation, or a dedicated CI-scoped key with a spend cap.

Invariants every sub-issue keeps

These are from AGENTS.md:

• No model runs in a write-capable job. The deterministic sweeps need no model. Nightly triage (Nightly triage: sweep unboarded issues onto the board and run the board audit #2463) does, and must use the three-job shape sdk-watch.yml established.
• A marker is trusted only on automation-authored issues, because the repo is public.
• Every action in a credentialed job is SHA-pinned (verify:action-pins).
• A sweep that cannot read its listing fails loudly and writes nothing.
• Accepting and publishing a security advisory stay human-gated; automation only creates tracking cards.

Done when

Every sub-issue is closed, and a nightly run boards what it files with no manual step.