remove otel.metricIntervalMs and the host-level otel.debug

Both are ignored with a warning through the same shim, now
nix/host-modules/hive-options-removed.nix.

- otel.metricIntervalMs: claude in every agent and hive-c0re's
  container-resource exporter run at the 60s default. The agent-level
  services.hyperhive.agent.otel.metricIntervalMs, set only by the meta
  render, goes too (warning shim in nix/agent-modules/otel-removed.nix).
- otel.debug: services.hyperhive.agent.otel.debug stays, documented and
  set in an agent's own config; the meta render no longer emits it.

nix/module-eval/agent-otel.nix

@@ -38,11 +38,13 @@ let
 
   # The same agent over the other wire protocol. An exporter's NAME is what
   # selects it, so this is where a defined exporter and the pipeline's
-  # reference to it can drift apart.
+  # reference to it can drift apart. Also an agent config still setting the
+  # removed metric interval.
   agentOtelGrpc = agent {
     otel.enable = true;
     otel.endpoint = agentBridge;
     otel.protocol = "grpc";
+    otel.metricIntervalMs = 10000;
   };
 
   agentNoOtel = shared.agentBare;
@@ -116,6 +118,22 @@ let
         in
         (s.exporters ? otlp) && s.service.pipelines.logs.exporters == [ "otlp" ];
     }
+    {
+      # Control: `agentOtel` sets no interval. The endpoint lookup shows the
+      # environment it reads is the one the OTEL SDKs get.
+      name = "an agent config setting the removed metric interval evaluates, warns, and exports none";
+      ok =
+        let
+          warned = lib.any (
+            w: lib.hasInfix "services.hyperhive.agent.otel.metricIntervalMs is removed and ignored" w
+          );
+          env = machine: machine.systemd.globalEnvironment;
+        in
+        warned agentOtelGrpc.warnings
+        && !(warned agentOtel.warnings)
+        && (env agentOtelGrpc) ? OTEL_EXPORTER_OTLP_ENDPOINT
+        && !((env agentOtelGrpc) ? OTEL_METRIC_EXPORT_INTERVAL);
+    }
   ];
 in
 runGroup "agent-otel" cases