jobq: restore the coordinator.md cross-reference

The \bJob\b pass rewrote a doc reference too: docs/coordinator.md::Job
queue became ::JobBuilder queue, pointing at a section that does not
exist. The section is still "## Job queue".

hive-c0re/src/job_queue/mod.rs

@@ -25,7 +25,7 @@
 //! The queue is runtime-only (no persistence): an empty graph on boot; desired
 //! state is re-derived by the reconcile sweep. A single scheduler task
 //! ([`scheduler::run_worker`]) drives it; concurrency comes from the build-slot
-//! capacity, not multiple workers. Design: `docs/coordinator.md::JobBuilder queue`.
+//! capacity, not multiple workers. Design: `docs/coordinator.md::Job queue`.
 
 pub mod exec;
 pub mod model;