feat(hive-c0re): replace rebuild queue with generic job-DAG queue

jobs are now DAGs of primitive nodes (prebuild, stop-for-update, swap,
reconcile, signal, drain, ...) driven by one scheduler with N build
slots + per-agent lifecycle leases. per-agent power intent (wanted
up/offline) is durable in agent_power.sqlite; Reconcile nodes converge
observed state to it. kills the graceful-stop watcher thread, the
deferred-start follow-up, and the cascade pre-enqueue (fan-out on
MetaLock completion instead). tracker: #2166

hive-c0re/src/dashboard/lifecycle_ops.rs

@@ -1,10 +1,12 @@
 //! Container lifecycle endpoints for the dashboard.
 //!
 //! Rebuild / restart / start / stop (hard + graceful) / update-all all
-//! enqueue onto the rebuild queue, so each shows a visible queued→running
-//! transient on the dashboard — a direct sub-second start/stop only flashed
-//! the badge; destroy delegates to `actions::destroy` (optionally
-//! purging).
+//! submit DAGs to the job queue (`job_queue::submit`), so each shows a
+//! visible queued→running transient on the dashboard — a direct
+//! sub-second start/stop only flashed the badge. Start/stop also
+//! persist the agent's `wanted` power intent before submitting; the
+//! DAG's `Reconcile` converges to it. Destroy delegates to
+//! `actions::destroy` (optionally purging).
 
 use axum::{
     extract::{Form, Path as AxumPath, Query, State},
@@ -23,6 +25,7 @@ pub(super) struct KillParams {
 }
 
 use super::{AppState, error_response, guard_agent_name, strip_container_prefix};
+use crate::job_queue::{Source, submit};
 use crate::{actions, lifecycle};
 
 pub(super) async fn post_rebuild(
@@ -33,14 +36,12 @@ pub(super) async fn post_rebuild(
     if let Some(reject) = guard_agent_name(&state, &logical).await {
         return reject;
     }
-    state.coord.rebuild_queue.enqueue(
-        crate::rebuild_queue::QueueKind::Rebuild,
-        logical,
-        crate::rebuild_queue::QueueSource::Manual,
+    submit::rebuild(
+        &state.coord,
+        &logical,
+        Source::Manual,
         "manual via dashboard ↻ R3BU1LD button".to_owned(),
-        None,
     );
-    state.coord.emit_rebuild_queue_snapshot();
     (StatusCode::OK, "ok").into_response()
 }
 
@@ -54,19 +55,17 @@ pub(super) async fn post_kill(
         return reject;
     }
     if params.graceful {
-        // Graceful stop: enqueue the quiesce orchestration (signal the harness
-        // → one stop-checkpoint turn → drain → container stop, with a timeout
-        // fallback to a hard stop). Serialised through the rebuild queue so it
-        // can't race an in-flight rebuild for the same agent, and its per-step
-        // progress surfaces on the queue snapshot + build log.
-        state.coord.rebuild_queue.enqueue(
-            crate::rebuild_queue::QueueKind::GracefulStop,
-            logical,
-            crate::rebuild_queue::QueueSource::Manual,
+        // Graceful stop: submit the quiesce DAG (signal the harness →
+        // one stop-checkpoint turn → drain → container stop, with a
+        // timeout fallback to a hard stop). The agent's lifecycle
+        // lease keeps it from racing an in-flight rebuild for the same
+        // agent, and per-node progress surfaces on the queue snapshot.
+        submit::graceful_stop(
+            &state.coord,
+            &logical,
+            Source::Manual,
             "manual via dashboard graceful stop".to_owned(),
-            None,
         );
-        state.coord.emit_rebuild_queue_snapshot();
         return (StatusCode::OK, "ok").into_response();
     }
     // Manager is stoppable from the dashboard like any other
@@ -79,14 +78,12 @@ pub(super) async fn post_kill(
     // `socket_server.rs::ManagerRequest::Kill` stays in place: a
     // manager calling Kill on its own container is self-suicide
     // mid-call, not a legitimate operator action.
-    state.coord.rebuild_queue.enqueue(
-        crate::rebuild_queue::QueueKind::Stop,
-        logical,
-        crate::rebuild_queue::QueueSource::Manual,
+    submit::stop(
+        &state.coord,
+        &logical,
+        Source::Manual,
         "manual via dashboard stop".to_owned(),
-        None,
     );
-    state.coord.emit_rebuild_queue_snapshot();
     (StatusCode::OK, "ok").into_response()
 }
 
@@ -98,14 +95,12 @@ pub(super) async fn post_restart(
     if let Some(reject) = guard_agent_name(&state, &logical).await {
         return reject;
     }
-    state.coord.rebuild_queue.enqueue(
-        crate::rebuild_queue::QueueKind::Restart,
-        logical,
-        crate::rebuild_queue::QueueSource::Manual,
+    submit::restart(
+        &state.coord,
+        &logical,
+        Source::Manual,
         "manual via dashboard ↺ R3START button".to_owned(),
-        None,
     );
-    state.coord.emit_rebuild_queue_snapshot();
     (StatusCode::OK, "ok").into_response()
 }
 
@@ -117,14 +112,12 @@ pub(super) async fn post_start(
     if let Some(reject) = guard_agent_name(&state, &logical).await {
         return reject;
     }
-    state.coord.rebuild_queue.enqueue(
-        crate::rebuild_queue::QueueKind::Start,
-        logical,
-        crate::rebuild_queue::QueueSource::Manual,
+    submit::start(
+        &state.coord,
+        &logical,
+        Source::Manual,
         "manual via dashboard start".to_owned(),
-        None,
     );
-    state.coord.emit_rebuild_queue_snapshot();
     (StatusCode::OK, "ok").into_response()
 }
 
@@ -137,15 +130,13 @@ pub(super) async fn post_update_all(State(state): State<AppState>) -> Response {
         else {
             continue;
         };
-        state.coord.rebuild_queue.enqueue(
-            crate::rebuild_queue::QueueKind::Rebuild,
-            logical,
-            crate::rebuild_queue::QueueSource::Manual,
+        submit::rebuild(
+            &state.coord,
+            &logical,
+            Source::Manual,
             "manual via dashboard 🌀 UPDATE ALL".to_owned(),
-            None,
         );
     }
-    state.coord.emit_rebuild_queue_snapshot();
     (StatusCode::OK, "ok").into_response()
 }