docs(CLAUDE.md): add network.md to file index + reading paths (follow-up to #845)

CLAUDE.md

@@ -310,6 +310,8 @@ docs/
                        HIVE_FORGE_URL loopback rationale (#764, #772, #793)
   matrix.md            matrix container shape, serverName/gatewayHost split,
                        firewall + federation, provisioning flow, fluffychat-web build
+  network.md           host-side bridge + dnsmasq resolver, v1/v2 roadmap,
+                       foundation for #14 netns isolation (#805)
 ```
 
 ## Reading paths
@@ -336,6 +338,8 @@ read them à la carte.
 - **"How does the matrix-tuwunel container work? What about
   fluffychat-web and per-agent matrix accounts?"** →
   [`docs/matrix.md`](docs/matrix.md).
+- **"How does DNS resolution work in agent containers? What's the
+  bridge network for?"** → [`docs/network.md`](docs/network.md).
 
 ## Conventions & process