In the file .claude/plugins/quacker-channel/src/acp_dispatch.rs, add a Rust doc comment (lines starting with ///) immediately above the line that begins `fn has_flat_tag(`, describing in one sentence what has_flat_tag does. Do not change any code logic and do not touch any other function or file. Then run: git add -A && git commit -m "doc: explain has_flat_tag".