[instructions] Add --fail-fast flag to compilation options

[github-actions]

Instructions Update - Synchronized with v0.40.1

This PR updates the github-agentic-workflows.md file to document the --fail-fast compilation flag introduced in v0.40.1.

Changes Made

• Added --fail-fast flag to the "Additional Compilation Options" section
• Documents that this flag stops compilation at the first validation error instead of aggregating all errors (the default behavior)

Documentation Commits Reviewed

Since v0.40.1 (2026-02-03), only one commit affected the repository:

• 143966b - Fix indentation in compiler_activation_jobs.go (non-documentation change)

Features Already Documented

The following v0.40.1 features were already documented in the instructions file:

• ✅ expires field for create-issue and create-pull-request safe-outputs
• ✅ remove-labels safe-output type with examples
• ✅ Discussion support (create, update, close, add comments)

Validation

• Followed prompting best practices (imperative mood, minimal example)
• Maintained technical tone and brevity
• Updated only necessary sections (3 line addition)
• Verified accuracy against current codebase (cmd/gh-aw/main.go:560)
• No outdated or redundant content removed (none found)

🤖 Generated with Claude Code

AI generated by Instructions Janitor

• expires on Feb 18, 2026, 11:57 PM UTC