The antigravity code-simplify command instructed the agent to read
"CLAUDE.md or AGENTS.md", but per docs/antigravity-setup.md the
Antigravity CLI reads AGENTS.md for project conventions. The CLAUDE.md
reference is a leftover from the Claude command variant. Align it with
the other platform commands, where each reads its own conventions file
(.claude reads CLAUDE.md, .gemini reads GEMINI.md).