kumi 1.5.0

Per-agent metrics now read each subagent's own transcript, count each message once and include the final message. Every hook has a 10 second timeout and shares one bounded input reader. Hook commands read the plugin root from the environment and run Python in isolated mode. CI checks that the version agrees across plugin.json, CHANGELOG.md and the tag. New kumi mark, lockup and brand images. See CHANGELOG.md for details.