[instructions] Sync github-agentic-workflows.md with v0.33.1

[github-actions]

Instructions Update - Synchronized with v0.33.1

This PR updates the github-agentic-workflows.md file based on documentation changes included in the v0.33.1 release (2025-12-16).

Changes Made

Added mentions configuration to safe-outputs:

• Documents the new mentions field for controlling @mention filtering in AI-generated content
• Supports boolean form (mentions: true) and object form with fine-grained control
• Object form options: allow-team-members, allow-context, allowed list, and max limit
• Default: 50 mentions per message
• Placed in Global Safe Output Configuration section alongside github-token

Added token fallback documentation for update-project:

• Documents automatic fallback chain: github-token → GH_AW_PROJECT_GITHUB_TOKEN → GITHUB_TOKEN
• Clarifies token resolution behavior for project operations

Documentation Commits Reviewed

• 487f48c Add automatic GH_AW_PROJECT_GITHUB_TOKEN fallback for update_project jobs

Release Context

Release: v0.33.1 (2025-12-16)
Previous Release: v0.33.0 (2025-12-15)

The v0.33.1 release introduced mention filtering configuration as a non-breaking enhancement to safe-outputs. This update ensures the instructions file accurately reflects current capabilities.

Validation

• ✅ Followed prompting best practices (imperative mood where applicable, minimal examples)
• ✅ Maintained technical tone and brevity
• ✅ Updated only necessary sections
• ✅ Verified accuracy against CHANGELOG and commit diffs
• ✅ Preserved existing structure and organization
• ✅ Added concise, actionable documentation

AI generated by Instructions Janitor