feat(packaging): ODoH client Docker deploy

Single-container docker-compose recipe for running numa in ODoH client
mode. Ships with a starter numa.toml pointing at odoh-relay.numa.rs
paired with Cloudflare's ODoH target — two independent operators with
distinct eTLD+1s, so the default passes numa's same-operator check.

Exposes :53 UDP+TCP for LAN clients and :5380 for the dashboard + REST
API. README covers prerequisites, deploy, verification, and the ODoH
privacy boundary (relay sees IP, target sees query, neither sees both).

Advertised alongside packaging/relay/ in the main README Docker section.

packaging/client/docker-compose.yml

@@ -0,0 +1,15 @@
+services:
+  numa:
+    image: ghcr.io/razvandimescu/numa:latest
+    command: ["/etc/numa/numa.toml"]
+    ports:
+      - "53:53/udp"
+      - "53:53/tcp"
+      - "5380:5380/tcp"    # dashboard + REST API
+    volumes:
+      - ./numa.toml:/etc/numa/numa.toml:ro
+      - numa_data:/var/lib/numa
+    restart: unless-stopped
+
+volumes:
+  numa_data: