nix: drop the central-toggle conjunct from four compound gates

`services.hyperhive.enable` is going away (Refs #4500). These four blocks
ANDed it with a second condition that was already the load-bearing one:
the bridge-firewall hole asks whether an operator named any
`network.exposeHostPorts`, and the three swarm-level services ask their
own `deploy.*.enable`, each of which defaults false (swarm-ui derives
from the controller's toggle, a sibling deployment decision) and none of
which is derived from the hive toggle. So dropping the conjunct turns
nothing on by itself — the remaining condition still decides.

The way that claim fails is by something becoming unconditional, so
module-eval gets absence arms for all four, each asserted on a host with
the hive ON and on one with it OFF, plus the two controls that make the
absences mean something.

The swarm-controller arm is probed by the credential oneshot and by the
daemon's `ExecStart` rather than by the unit name: hive-tls defines an
environment key on that name, which leaves an inert fragment behind on
any hive with a CA whether or not the controller runs there.

nix/host-modules/hive-network.nix

@@ -276,7 +276,7 @@ in
     # is firewall-only by design: a host service that binds `0.0.0.0` already
     # serves the bridge IP, so an extra bridge-IP proxy would only collide
     # (EADDRINUSE) with it. Merges with the [ 80 443 ] gateway ports above.
-    (lib.mkIf (config.services.hyperhive.enable && cfg.exposeHostPorts != [ ]) {
+    (lib.mkIf (cfg.exposeHostPorts != [ ]) {
       networking.firewall.interfaces.${cfg.bridgeName}.allowedTCPPorts = cfg.exposeHostPorts;
     })
   ];

nix/host-modules/swarm-controller.nix

@@ -698,7 +698,7 @@ in
     };
   };
 
-  config = lib.mkIf (config.services.hyperhive.enable && deployCfg.swarm-controller.enable) {
+  config = lib.mkIf deployCfg.swarm-controller.enable {
     # The daemon and the oneshot that mints its credential — the second one
     # failing leaves the first running and unable to authenticate anywhere.
     services.hyperhive.swarm.otel.journaldUnits = [

nix/host-modules/swarm-otel.nix

@@ -563,7 +563,7 @@ in
     };
   };
 
-  config = lib.mkIf (config.services.hyperhive.enable && deployCfg.swarm-otel.enable) {
+  config = lib.mkIf deployCfg.swarm-otel.enable {
     # The gateway name, inside `deployCfg.swarm-otel.enable` — that guard is the load-bearing
     # part. Every hive in a swarm may know this collector exists, but only
     # the host that RUNS it may claim the name; a client hive declaring the

nix/host-modules/swarm-ui.nix

@@ -97,7 +97,7 @@ in
     '';
   };
 
-  config = lib.mkIf (config.services.hyperhive.enable && deployCfg.swarm-ui.enable) {
+  config = lib.mkIf deployCfg.swarm-ui.enable {
     assertions = [
       {
         # The `_` default server already answers for the hive domain

nix/module-eval.nix

@@ -491,6 +491,43 @@ let
     machine:
     machine.networking.firewall.interfaces.${machine.services.hyperhive.network.bridgeName}.allowedTCPPorts;
 
+  # Same list, on a host that may not declare the interface at all: the
+  # `[ 80 443 ]` block is what creates the attr, and it is off where the hive
+  # is. Reading it through `bridgePorts` would throw rather than report an
+  # empty exposure, which is precisely the state the cases below assert.
+  bridgePortsOrNone =
+    machine:
+    (machine.networking.firewall.interfaces.${machine.services.hyperhive.network.bridgeName} or {
+      allowedTCPPorts = [ ];
+    }
+    ).allowedTCPPorts;
+
+  # A host that installs the modules and turns nothing on. The per-service
+  # deployment toggles are what decide whether the swarm-level services render
+  # here, and none of them is derived from the hive being on, so this renders
+  # the same absences `bare` does — the arms below assert both, because a
+  # service that had quietly become unconditional would still look right on
+  # only one of them.
+  centralToggleOff = hive { enable = false; };
+
+  # Ports asked for on such a host. The request is the whole condition: the
+  # firewall hole exists because an operator named a port, not because the
+  # hive is running, and an agent reaching a host service is a claim about
+  # the host's own listeners either way.
+  exposedPortsNoHive = hive {
+    enable = false;
+    network.exposeHostPorts = [ 5432 ];
+  };
+
+  # The swarm UI where its own toggle is on — the control the absence arm
+  # needs, since nothing else in this suite renders this vhost and an arm
+  # saying "it is not there" would hold just as well if it were never there.
+  # Package stubbed per this file's header: the vhost roots at it.
+  swarmUiHere = hive {
+    deploy.swarm-ui.enable = true;
+    deploy.swarm-ui.package = pkgs.emptyDirectory;
+  };
+
   baoTwoAddresses = hive {
     deploy.bao.enable = true;
     deploy.bao.extraListenAddresses = [ "10.0.0.1" ];
@@ -3032,6 +3069,70 @@ let
         in
         !(s.listener ? metrics) && !(s ? telemetry);
     }
+    {
+      # The four blocks below used to be gated on the hive being enabled AND
+      # their own condition. The second half was always the load-bearing one —
+      # none of these conditions is derived from the hive toggle — so these
+      # arms pin what the conjunct was doing: nothing. Each is written against
+      # a host with the hive OFF as well as one with it on, because the way a
+      # dropped conjunct fails is by making something unconditional, and that
+      # shows up as a service appearing where nothing asked for it.
+      name = "no bridge port is opened for an exposeHostPorts nobody set";
+      ok =
+        !(builtins.elem 5432 (bridgePortsOrNone bare))
+        && !(builtins.elem 5432 (bridgePortsOrNone centralToggleOff));
+    }
+    {
+      # Control for the arm above, and the one place this slice is not inert:
+      # the ports are opened because they were named, on a host that never
+      # turned the hive on. The bridge firewall is the host's own, so there is
+      # nothing here for the hive toggle to have been protecting.
+      name = "a named exposeHostPorts opens its bridge port on the host's own say-so";
+      ok = builtins.elem 5432 (bridgePortsOrNone exposedPortsNoHive);
+    }
+    {
+      # `deploy.swarm-controller.enable`, which defaults false and is
+      # deliberately not derived from the hive toggle — a swarm has one
+      # controller, so the host that runs it says so itself.
+      #
+      # Probed by what the daemon needs in order to run, not by
+      # `? swarm-controller`: ./host-modules/hive-tls.nix defines an
+      # environment key on that unit name, which leaves the attr
+      # present-but-inert (no `ExecStart`, empty `wantedBy`) on every hive
+      # that has a CA — see the comment there. The credential oneshot has no
+      # second definer, so its absence is the unambiguous half.
+      name = "the swarm controller does not run unless this host is told to run it";
+      ok =
+        let
+          inert =
+            machine:
+            !(machine.systemd.services ? swarm-controller-credential)
+            && !(
+              (machine.systemd.services.swarm-controller or { serviceConfig = { }; }).serviceConfig ? ExecStart
+            );
+        in
+        inert bare && inert centralToggleOff;
+    }
+    {
+      # `deploy.swarm-otel.enable`, same shape: the swarm's collector is one
+      # host's job, and the container is the whole of what it renders.
+      name = "the swarm collector container is absent unless this host is told to run it";
+      ok = !(bare.containers ? swarm-otel) && !(centralToggleOff.containers ? swarm-otel);
+    }
+    {
+      # `deploy.swarm-ui.enable`, which defaults to the controller's toggle —
+      # derived from a sibling deployment decision, still not from the hive
+      # toggle. `t.local` is the fixtures' swarm domain, which is the apex the
+      # UI claims; the arm below is what proves this vhost renders at all.
+      name = "the swarm UI vhost is absent unless this host is told to serve it";
+      ok =
+        !(bare.services.nginx.virtualHosts ? "t.local")
+        && !(centralToggleOff.services.nginx.virtualHosts ? "t.local");
+    }
+    {
+      name = "the swarm UI claims the swarm apex where this host serves it";
+      ok = swarmUiHere.services.nginx.virtualHosts ? "t.local";
+    }
   ];
 
   bad = builtins.filter (c: !c.ok) cases;