ci: readiness gate for issues created through the API or CLI #2571

Goal

Apply the issue-template contract to issues that bypass issue forms.

Background

Issue forms apply only to issues created in the web UI. Agents and basectl gh issue create create issues through the REST API, so they bypass the required sections. The readiness checker (basectl gh issue readiness) is read-only and run by hand, and the Project Intake workflow is explicitly advisory.

Next-release planning review of 2026-10-14/15 against main at 7faf6dfb. Tracking: #2555.

Scope

• A workflow on issues: opened and edited that runs the body-level readiness check (required sections present and non-empty, size L split note).
• Post one updatable comment and apply or clear a single label (name decided in the PR).
• Be idempotent and not trigger on its own edits.

Acceptance Criteria

• An issue missing required sections receives exactly one comment and the label within minutes.
• Fixing the body clears the label and updates the comment.
• Issue creation is never blocked.
• Behavior is covered by the workflow contract tests.

Validation

git diff --check
python -m pytest tests/test_github_workflows.py tests/test_project_intake_workflow.py

Non-Goals

• Do not auto-close issues.
• Do not duplicate the Project field sync done by Project Intake.

Project Fields

• Status: Ready
• Priority: P2
• Area: CI
• Initiative: Agentic Coding Platform
• Size: M
• Milestone: v1.13.0
• Category: ci

Agent Assignment

Assignee: codeforester. Implementation-ready; use an issue-backed worktree.

Plan revision (2026-10-16)

This issue is intentionally scheduled for v1.13.0, after the v1.12.0 assignment schema and loop contract have stabilized. Add #2573 as a prerequisite. The gate must validate the structured Agent Assignment fields that the loop consumes, not just section presence, while preserving the non-blocking/idempotent behavior described above. Its output is a prerequisite for controller L2 and the pilots; it does not authorize any write or merge action.