chore: remove AI instructions and gitignore them

Signed-off-by: Huang, Zeyu <11222265+fhfuih@users.noreply.github.com>

Author: fhfuih

.gitignore

@@ -153,6 +153,14 @@ dmypy.json
 # Cython debug symbols
 cython_debug/
 
+# Claude
+CLAUDE.md
+.claude/
+
+# Codex
+AGENTS.md
+.codex/
+
 # cursor
 .cursor/