v0.30.0-nightly: Sub-agents, external editors, and shell autocomplete v0.30.0-nightly.20260227.9b7852f11

Kind.Agent landed for proper sub-agent classification, plans now open in your editor of choice, and the CLI autocompletes like it actually respects your time. Also renamed grep_search include to include_pattern because consistency matters. Nightly build, so consider it a sneak peek at what's cooking.