hive-c0re/hivectl/hive-agent: pause as a job-queue DAG node (closes #3056)

hive-c0re/src/job_queue/model.rs

@@ -119,6 +119,16 @@ pub enum NodeKind {
     /// `GRACEFUL_STOP_TIMEOUT`. Resolves ok either way — the
     /// downstream `Reconcile` performs the actual stop.
     Drain { agent: String },
+    /// Write the pause marker (`Coordinator::set_paused`) + mark
+    /// `pause_pending`. No kick, unlike `Signal` — the harness's own
+    /// between-turns poll (`PAUSE_POLL`, 1s default) is already
+    /// responsive enough, and `Signal`'s kick-message body ("you were
+    /// just (re)started") would be actively misleading here.
+    PauseSignal { agent: String },
+    /// Await the harness reporting `PauseAcknowledged`, bounded by a
+    /// timeout. Resolves ok either way — pausing is best-effort from
+    /// the queue's perspective, same as `Drain`.
+    PauseDrain { agent: String },
     /// `set_nspawn_flags` + `set_resource_limits` + daemon-reload.
     WriteDropin { agent: String },
     /// Commit `tool-groups.json` / `capabilities.json` per its `payload`
@@ -338,6 +348,8 @@ impl NodeKind {
             NodeKind::StopForUpdate { .. } => "stop_for_update",
             NodeKind::Signal { .. } => "signal",
             NodeKind::Drain { .. } => "drain",
+            NodeKind::PauseSignal { .. } => "pause_signal",
+            NodeKind::PauseDrain { .. } => "pause_drain",
             NodeKind::WriteDropin { .. } => "write_dropin",
             NodeKind::WritePermFile { .. } => "write_perm_file",
             NodeKind::Reparent { .. } => "reparent",
@@ -372,6 +384,8 @@ impl NodeKind {
             | NodeKind::StopForUpdate { agent }
             | NodeKind::Signal { agent }
             | NodeKind::Drain { agent }
+            | NodeKind::PauseSignal { agent }
+            | NodeKind::PauseDrain { agent }
             | NodeKind::WriteDropin { agent }
             | NodeKind::WritePermFile { agent, .. }
             | NodeKind::DeployWindow { agent, .. }