chore: remove agentic workflows from PR scope

Remove all GitHub Agentic Workflow files (.github/workflows/agent-*,
.github/agents/, .github/aw/) and clean up related references in
AGENTS.md, docs, .prettierignore, and .gitattributes. This PR now
focuses solely on harness engineering improvements.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: tudorpopams

.gitattributes

@@ -3,5 +3,3 @@
 
 # API files should be checked in with Unix-style newlines
 *.api.md text=auto
-
-.github/workflows/*.lock.yml linguist-generated=true merge=ours