hive-c0re: the per-agent resource limit override is gone

The hive no longer sets an agent's CPU or memory cap: caps come from the swarm, else the hive-wide defaults. The container load tab was the only hive UI that set them, and its figures are already exported as OTEL metrics, so with the tab gone nothing wrote meta/resource-limits.json.

Removed: the file's reader and writer, the `hivectl agent set-limits` verb with its host-socket request, the `GET /api/container-resources` and `POST /api/resource-limits/{name}` dashboard endpoints, and the `cpu_quota`/`memory_max` fields of the container view that only the tab read. A leftover resource-limits.json is ignored.

hive-c0re/src/coordinator.rs

@@ -720,7 +720,7 @@ impl Coordinator {
     pub async fn rescan_containers_and_emit(self: &Arc<Self>) {
         // An unreadable list says nothing about which containers exist, so
         // the last snapshot stands rather than every row being reported gone.
-        let fresh = match container_view::build_all(&self.hive_env()).await {
+        let fresh = match container_view::build_all().await {
             Ok(fresh) => fresh,
             Err(e) => {
                 tracing::warn!(error = ?e, "container rescan: list failed; keeping last snapshot");