feat: add handoff lint #122

Job	Run time
test (3.12)	15s
test (3.11)	19s
install-from-source (kitchen-sink, --depth workspace --harnesses claude,codex,openclaw,hermes)	20s
install-from-source (repo+codex, --depth repo --harnesses codex)	12s
content-guard	9s
install-from-source (workspace+claude+openclaw, --depth workspace --harnesses claude,openclaw)	17s
install-from-source (workspace+none, --depth workspace --harnesses none)	12s
install-from-source (workspace+codex+openclaw, --depth workspace --harnesses codex,openclaw)	13s
install-from-source (repo+claude+publisher, --depth repo --harnesses claude --include publisher)	12s
test (3.10)	15s
install-from-source (repo+claude, --depth repo --harnesses claude)	15s
	2m 39s

Provide feedback