Initial CoreDNS setup as MCNS precursor

Serves two internal zones for the Metacircular platform:
- svc.mcp.metacircular.net (service addresses)
- mcp.metacircular.net (node addresses)

Forwards all other queries to 1.1.1.1 and 8.8.8.8. Includes rift
deployment compose with CoreDNS 1.12.1 and zone files mapping
metacrypt and rift to their LAN and Tailscale addresses.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

zones/mcp.metacircular.net.zone

@@ -0,0 +1,26 @@
+; Node addresses for Metacircular platform.
+; Maps node names to their network addresses.
+;
+; When MCNS is built, these will be managed via the MCNS API.
+; Until then, this file is manually maintained.
+
+$ORIGIN mcp.metacircular.net.
+$TTL 300
+
+@   IN SOA  ns.mcp.metacircular.net. admin.metacircular.net. (
+        2026032501  ; serial (YYYYMMDDNN)
+        3600        ; refresh
+        600         ; retry
+        86400       ; expire
+        300         ; minimum TTL
+    )
+
+    IN NS   ns.mcp.metacircular.net.
+
+; --- Nodes ---
+rift    IN A    192.168.88.181
+rift    IN A    100.95.252.120
+
+; ns record target — points to rift where CoreDNS runs.
+ns      IN A    192.168.88.181
+ns      IN A    100.95.252.120