chore: add site/ and IDEATION_*.md to gitignore

- site/: MkDocs build artifact
- IDEATION_*.md: Design brainstorming documents

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: grokify

.gitignore

@@ -10,4 +10,8 @@ main.zip
 
 # Build artifacts
 agentcall
-agentcomms
+agentcomms
+site/
+
+# Ideation documents
+IDEATION_*.md