fix: use forge domain URL + open 80/443 for isolated agents

when isolateContainers=true, isolated agents have dnsmasq as their
resolver — forge.<domain> resolves to bridgeIp. route HIVE_FORGE_URL
through nginx on port 80 instead of exposing the raw forge port.

- HIVE_FORGE_URL: http://<forge.domain> when isolated (nginx proxies)
- bridge firewall: open 80+443 for agents to reach nginx (gateway)
- remove forge-specific httpPort rule (no longer needed)
- update docs/gateway.md + docs/network.md

per mara's review comment on PR #1150.

docs/gateway.md

@@ -200,27 +200,22 @@ dashboard reach by design — the surface is privileged (approve /
 deny / destroy) and must not be exposed without a real reverse
 proxy in front.
 
-## `HIVE_FORGE_URL`: bridge gateway for isolated agents, loopback for shared-netns
+## `HIVE_FORGE_URL`: domain via gateway for isolated agents, loopback for shared-netns
 
 Agents poll `HIVE_FORGE_URL` for Forgejo notifications + run all
 `hive-forge` calls against it. `hive-c0re.nix` sets this based on the
 network isolation mode:
 
-- **`network.isolateContainers = true`**: agents run in private netns,
+- **`network.isolateContainers = true`**: agents run in private netns and
-  so host loopback is unreachable. `HIVE_FORGE_URL` is set to
+  get the bridge dnsmasq as their resolver. `HIVE_FORGE_URL` is set to
-  `http://<bridgeIp>:<forge.httpPort>`. Forgejo binds `0.0.0.0` so it's
+  `http://<forge.domain>` (default `forge.<hive-domain>`). Agents resolve
-  reachable at the bridge gateway IP. `hive-network.nix` opens
+  the hostname via dnsmasq → bridge IP, then reach nginx on port 80 (bridge
-  `forge.httpPort` on the bridge interface automatically.
+  firewall opens 80+443 when isolation is on). nginx proxies to forgejo — the
+  same path an operator browser takes, no raw port exposure needed.
 - **`network.isolateContainers = false`** (default): agents share the host's
   network namespace, so loopback reaches forgejo directly. `HIVE_FORGE_URL`
   is `http://127.0.0.1:<forge.httpPort>`.
 
-The sub-domain default (`forge.<hive-domain>`) is for **operator
-browsers + cross-host clients**, not in-cluster traffic. Using the
-sub-domain URL inside agent containers would fail every `hive-forge`
-invocation with "Name or service not known" — the agent's nspawn
-doesn't have DNS for the external hostname.
-
 ## hive-forge container shape
 
 Private Forgejo wrapped in a nixos-container (`hive-forge`, not

docs/network.md

@@ -95,6 +95,11 @@ agent containers.
 interface only. Other interfaces stay closed. The hive resolver
 isn't an external-facing service.
 
+When `isolateContainers = true`, `allowedTCPPorts` is extended with
+`[ 80 443 ]` so isolated agents can reach nginx (gateway container,
+shared host netns) for the forge sub-domain, per-agent UI proxies,
+and any other HTTP services.
+
 ## Container isolation
 
 `services.hyperhive.network.isolateContainers` (default `false`) flips
@@ -108,8 +113,8 @@ agent containers from shared host netns to private netns. Set only after
 | IP forwarding | `boot.kernel.sysctl."net.ipv4.ip_forward" = 1` |
 | Internet NAT | `networking.nat { enable = true; internalInterfaces = [ bridgeName ]; }` — MASQUERADE on packets leaving via any external NIC |
 | Loopback DROP | `networking.firewall.extraInputRules` — drops bridge-subnet → `127.0.0.0/8` traffic; defence-in-depth against routing table leaks |
-| Forge access | `networking.firewall.interfaces.<bridge>.allowedTCPPorts` — opens `forge.httpPort` on the bridge interface so isolated agents can reach forgejo at `<bridgeIp>:<httpPort>` |
+| Gateway access | `networking.firewall.interfaces.<bridge>.allowedTCPPorts = [ 80 443 ]` — lets isolated agents reach nginx on the host (shared netns) |
-| Forge URL | `HIVE_FORGE_URL` flips from `http://127.0.0.1:3000` to `http://<bridgeIp>:3000` — forwarded to containers via meta flake |
+| Forge URL | `HIVE_FORGE_URL` flips from `http://127.0.0.1:3000` to `http://forge.<domain>` — agents resolve via dnsmasq, nginx proxies to forgejo |
 | c0re signal | `HIVE_NETWORK_ISOLATION=1`, `HIVE_NETWORK_BRIDGE`, `HIVE_NETWORK_SUBNET` in `systemd.services.hive-c0re.environment` |
 
 `HIVE_NETWORK_SUBNET` is the host-side bridge IP + prefix (e.g.

nix/modules/hive-c0re.nix

@@ -557,17 +557,17 @@ in
         HYPERHIVE_SWARM_NAME = config.services.hyperhive.swarmName;
       }
       // lib.optionalAttrs config.services.hyperhive.forge.enable {
-        # In-cluster forge URL. When containers are isolated (private netns),
+        # In-cluster forge URL.
-        # 127.0.0.1 is the container's own loopback — unreachable for host
+        # - Isolated (private netns): containers resolve `forge.<domain>` via
-        # services. Use the bridge gateway IP instead; forgejo binds 0.0.0.0
+        #   the bridge dnsmasq and reach nginx on port 80. No raw forge port
-        # so it's reachable there. Shared-netns mode keeps loopback path.
+        #   needed — nginx proxies to forgejo as it does for the operator.
-        # External `forge.<hive>` sub-domain isn't DNS-resolvable from inside
+        # - Shared netns: host loopback is reachable, use direct port.
-        # nspawn either way. See `docs/gateway.md::HIVE_FORGE_URL`.
+        # See `docs/gateway.md::HIVE_FORGE_URL`.
         HIVE_FORGE_URL =
           if
             config.services.hyperhive.network.enable && config.services.hyperhive.network.isolateContainers
           then
-            "http://${config.services.hyperhive.network.bridgeIp}:${toString config.services.hyperhive.forge.httpPort}"
+            "http://${config.services.hyperhive.forge.domain}"
           else
             "http://127.0.0.1:${toString config.services.hyperhive.forge.httpPort}";
       }

nix/modules/hive-network.nix

@@ -215,16 +215,13 @@ in
         ip saddr ${cfg.bridgeIp}/${toString cfg.bridgePrefixLength} ip daddr 127.0.0.0/8 drop
       '';
 
-      # Allow isolated agents to reach the forge via the bridge gateway IP.
+      # Allow isolated agents to reach the gateway (nginx on the host, shared
-      # Forgejo binds 0.0.0.0 so it's reachable at `bridgeIp:httpPort` from
+      # netns). Port 80 covers `http://forge.<domain>`, per-agent UI proxies,
-      # inside agent containers; without this rule the default INPUT policy
+      # and any other HTTP services the gateway fronts. Port 443 for HTTPS.
-      # drops the connection before it reaches forgejo. Only added when forge
+      networking.firewall.interfaces.${cfg.bridgeName}.allowedTCPPorts = [
-      # is enabled — no-op otherwise.
+        80
-      networking.firewall.interfaces.${cfg.bridgeName}.allowedTCPPorts =
+        443
-        lib.optionals config.services.hyperhive.forge.enable
+      ];
-          [
-            config.services.hyperhive.forge.httpPort
-          ];
 
       # Tells hive-c0re to pass PRIVATE_NETWORK + bridge settings to each
       # container. HIVE_NETWORK_SUBNET is host-bridge IP/prefix, not canonical