wip(#3001): remove submit layer, rescue power ops into job_queue/power.rs

TREE IS RED ON PURPOSE — there is no compiling intermediate between
deleting submit and converting every caller. Checkpoint commit so the
work is durable; do not "fix" it by restoring submit.

Done:
- JobQueue::submit -> JobQueue::insert (no source/reason/container;
  returns the ids insert_job names).
- submit.rs deleted. Its 6 pure chain builders + 3 async *_many
  gatherers were NOT wrapper code and are rescued into
  job_queue/power.rs (templates.rs documents power ops as living
  outside it, because their shape needs a live is_running read).
- Converted: meta_inputs 1, topology 2, permissions 3, auto_update 2,
  actions 3, lifecycle_handlers 3.
- Dropped source/reason at every converted site: nothing ever read
  NodeKind::Dag's fields (only `{ .. }` matches exist), so they are
  write-only. Dead reason-only locals deleted; the boot sweep's summary
  became a tracing::info! rather than being lost.

Remaining: dashboard/lifecycle_ops 7, server.rs 7, and the test suite —
tests.rs has its own submit() helper whose u64 return is used as the
handle to navigate the inserted DAG, so those need a different way to
find nodes, not a mechanical port.

hive-c0re/src/socket_server/lifecycle_handlers.rs

@@ -20,13 +20,9 @@ pub(super) async fn handle_start(coord: &Arc<Coordinator>, agent: &str, name: &s
     // Persist `wanted = Up` and submit the Start DAG; the submit layer
     // upgrades a stale-rev start to a full rebuild so the container
     // runs current nix derivations before it starts.
-    crate::job_queue::submit::start(
-        coord,
-        name,
-        crate::job_queue::Source::Manual,
-        format!("agent `{agent}` start tool"),
-    )
-    .await;
+    if let Err(e) = crate::job_queue::power::start_many(coord, &[name.to_owned()]).await {
+        tracing::error!(%agent, %name, error = ?e, "start: insert failed");
+    }
     Response::Ok
 }
 
@@ -48,13 +44,9 @@ pub(super) async fn handle_restart(coord: &Arc<Coordinator>, agent: &str, name:
         return err;
     }
     tracing::info!(%agent, %name, "submit restart");
-    crate::job_queue::submit::restart(
-        coord,
-        name,
-        crate::job_queue::Source::Manual,
-        format!("agent `{agent}` restart tool"),
-    )
-    .await;
+    if let Err(e) = crate::job_queue::power::restart_many(coord, &[name.to_owned()], false).await {
+        tracing::error!(%agent, %name, error = ?e, "restart: insert failed");
+    }
     Response::Ok
 }
 
@@ -153,12 +145,13 @@ pub(super) fn handle_update(coord: &Arc<Coordinator>, agent: &str, name: &str) -
         return err;
     }
     tracing::info!(%agent, %name, "submit rebuild");
-    crate::job_queue::submit::rebuild(
-        coord,
-        name,
-        crate::job_queue::Source::Manual,
-        format!("agent `{agent}` update tool"),
-    );
+    if let Err(e) = coord.job_queue.insert(|b| {
+        crate::job_queue::templates::rebuild(b, name, true);
+        Vec::new()
+    }) {
+        tracing::error!(%agent, %name, error = ?e, "update: insert failed");
+    }
+    coord.emit_rebuild_queue_snapshot();
     Response::Ok
 }