Remove internal development artifacts from tracking

Untrack ralph-build.md, ralph-ideation.md, ideation-log.md, and
CLAUDE.md — these are local development files, not part of the
distributed project. Added to .gitignore.

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

Author: unknown

.gitignore

@@ -7,3 +7,7 @@ __pycache__/
 *.pyc
 examples/*/package-lock.json
 scripts/batch-runs*.sh
+
+ralph-*.md
+ideation-log.md
+CLAUDE.md