In-flight run counts and queue depth

The "is the system backed up?" glance. Takes no parameters.

Two different scopes in one response, which is easy to misread:

• runs counts non-terminal runs in the CALLER'S WORKSPACE — pending (queued, not yet picked up), running, paused. Terminal runs are never counted; the three keys are always present, zero included.
• queue and keel are INSTANCE-WIDE Redis queue depths, not workspace-scoped: waiting (jobs queued), processing (claimed by a worker), dead (dead-lettered after redelivery). queue is the workflow-run lane; keel is the AI-assistant chat lane.

When the queue cannot be read (Redis unreachable, or the instance has no queue wired) the block degrades to {"available": false} with the three counters ABSENT — deliberately, rather than reporting misleading zeros. Always check available before reading the counters.