[instructions] Sync instruction files with release v0.84.2

[github-actions]

Overview

Syncs internal instruction/skill docs (.github/aw/*.md) with upstream release v0.84.2. Consolidates duplicated security guidance into workflow-constraints.md references and corrects stale engine capability notes. Documentation-only change; no code or workflow behavior is affected.

Key changes

• Security guidance consolidation: create-agentic-workflow.md, github-agentic-workflows.md, and update-agentic-workflow.md now point to workflow-constraints.md for the read-only job / safe-outputs: routing posture instead of repeating it inline.
• github-agentic-workflows.md: also condenses the non-technical persona examples table to reference the existing Persona-to-Pattern Quick Matrix rather than duplicating trigger/output columns.
• safe-outputs-content.md: documents the create_discussion body validation minimum of 64 characters.
• Gemini engine docs corrected (syntax-agentic.md, syntax-engine.md): removed the outdated claim that gemini doesn't support max-turns; it now only excludes web-search.

File-level detail

File	Change
.github/aw/create-agentic-workflow.md	Refactored read-only guidance to reference workflow-constraints.md; removed duplicate safe-outputs bullet
.github/aw/github-agentic-workflows.md	Moved detailed security posture to workflow-constraints.md; simplified bash-access wording; condensed persona table
.github/aw/safe-outputs-content.md	Added create_discussion body min-length (64 chars) note
.github/aw/syntax-agentic.md	Removed stale "gemini doesn't support max-turns" note
.github/aw/syntax-engine.md	Updated gemini engine line: only web-search unsupported (was: max-turns, web-fetch, web-search)
.github/aw/update-agentic-workflow.md	Reorganized read-only/safe-outputs bullets into a workflow-constraints.md reference

Notes

Single commit, documentation-only sync (6 files under .github/aw/). No tests or compilation required.

Generated by PR Description Updater for #49739 · auto · 43 AIC · ⌖ 4.68 AIC · ⊞ 6.9K · ◷

[github-actions]

Great work on this documentation sync! 🎯 The accuracy fixes (Gemini engine support corrections), documentation of the 64-character create-discussion body minimum, and duplication reduction (consolidating security posture guidance) are all well-reasoned and verified against the source code.

The PR maintains excellent focus across the instruction files:

• Removes false claims about engine feature support
• Documents previously-unmentioned validation constraints
• Reduces redundancy while preserving clarity through cross-references
• Keeps all files under their line limits

The detailed explanation comparing v0.84.2 commits and verifying changes against implementation files shows thorough diligence. This is exactly how internal documentation maintenance automation should work — focused, well-documented, and confidence-building for reviewers.

This looks ready to merge. ✨

Generated by ✅ Contribution Check · auto · 51.3 AIC · ⌖ 4.74 AIC · ⊞ 8.7K · ◷

[github-actions]

🎉 This pull request is included in a new release.

Release: v0.84.3