Improve DX Skills for GitHub Issue and PR Management Following dotCMS Rules

Description

The claude GitHub DX tooling started with a single create-issue skill — a 232-line, CREATE-only Claude Code skill that could file a new issue but had no support for updates, queries, sprint lookups, or PR management.

Issue #34800 replaced that with the multi-mode dotcms-github-issues skill (CREATE · UPDATE · QUERY · FIND), adding team caching, native GitHub issue types, Project #7 field automation, sprint iteration awareness, and sub-issue linking.

This epic continues that evolution: extending the skill layer to cover pull requests with the same dotCMS conventions, and ensuring shared logic (team labels, Type labels, Technology mapping) is read from authoritative sources rather than maintained in duplicate static tables.

Desired Outcome

• A dedicated PR skill that mirrors dotcms-github-issues conventions: team labels, Type labels, native GitHub types, Project #7 Technology field, and issue linkage
• Skills read from authoritative sources (.github/ISSUE_TEMPLATE/, .github/PULL_REQUEST_TEMPLATE/) rather than maintaining duplicate static tables
• Enablement team members can create, update, query, and find both issues and PRs entirely through AI-assisted skills without needing to know underlying gh CLI syntax

Target Personas

• Developer teams

Links

• Before: create-issue skill — original single-mode skill (superseded)
• Issue #34800: Replace create-issue with multi-mode dotcms-github-issues
• Issue #34821: Create a skill for GitHub PR management

Start by reading the existing .claude/skills/create-issue/ skill and the conventions introduced by issue #34800, then inspect .github/ISSUE_TEMPLATE/ and .github/PULL_REQUEST_TEMPLATE/. Use issue #34821 as the PR-management scope. Done means issue and PR skills support create, update, query, and find workflows while reading shared conventions from those authoritative templates.