* feat(agent): expose read-only run status tool
* refactor(tools): name the subagent dispatch tool set
Hoist the hardcoded subagent dispatch tool-name literal into _SUBAGENT_DISPATCH_TOOL_NAMES so a future dispatch-tool rename has one place to update. No behavior change: the folded-subagent context_fill guard compares the same two names.
* test(tools): account for run status in collision assembly
* docs: keep script guidance within size budget
