Enforce machine-readable epic dependency graphs

[jpapiez]

Summary

Add producer-side verification so type:epic issues cannot silently ship with sub-issues but no machine-readable dependency graph.

Scope

• Add a CI verifier and workflow for epic sub-issue dependency edges.
• Add an exact operational skill for creating and reading dependency/sub-issue links.
• Add a concise epic definition-of-done to the Dallas charter and shared guidance if warranted.

Motivation

Epic #2410 initially encoded its dependency graph only as prose, so downstream automation had no edges to consume and a blocked documentation issue was picked up prematurely. The epic has since been corrected manually; this issue tracks preventive Squad process infrastructure only.

Acceptance criteria

• The verifier passes on corrected epic Epic: iOS navigation redesign — A′ · Two Hats, adaptive #2410.
• The verifier fails on an epic with children but no graph unless an explicit flat-graph opt-out is declared.
• Isolated child issues outside the declared first wave are reported.
• The workflow surfaces the result without modifying the existing blocked-label synchronization workflow.
• The operational skill documents the global issue ID and integer -F API requirements.
• Dallas epic completion guidance requires linked sub-issues and verified API dependency edges.

[github-actions]

📋 Assigned to ⚙️ Parker (DevOps & Deployment Engineer)

Issue: #2432 — Enforce machine-readable epic dependency graphs

⚙️ Parker will pick this up in the next Copilot session.

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⚙️ Parker, work on issue #2432

[jpapiez]

Owner: ⚙️ Parker (squad:parker). First step: add a CI verifier script that reads epic sub-issue graphs via the GitHub sub_issues API and fails when an epic has children but no dependency edges, per the acceptance criteria. Priority p2 — preventive process infra, not user-facing.