Add Technitium DNS stack for syn02 cluster node

- Deploy secondary Technitium DNS node on syn02
- Host networking for DNS port 53 access
- 2GB memory limit, security hardening
- Storage: /volume2/docker/technitium/config

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

stacks/technitium_syn02.compose.yml

@@ -0,0 +1,14 @@
+services:
+  technitium:
+    image: technitium/dns-server:latest
+    container_name: Technitium
+    mem_limit: 2g
+    cpu_shares: 768
+    security_opt:
+      - no-new-privileges:true
+    network_mode: host
+    volumes:
+      - /volume2/docker/technitium/config:/etc/dns:rw
+    environment:
+      TZ: America/Los_Angeles
+    restart: on-failure:5