feat(dns): add db-backed DNS provider, domain, and record management with ops UI support

ts/dns/providers/factory.ts

@@ -0,0 +1,31 @@
+import type { IDnsProviderClient } from './interfaces.js';
+import type {
+  TDnsProviderType,
+  TDnsProviderCredentials,
+} from '../../../ts_interfaces/data/dns-provider.js';
+import { CloudflareDnsProvider } from './cloudflare.provider.js';
+
+/**
+ * Instantiate a runtime DNS provider client from a stored DnsProviderDoc.
+ *
+ * @throws if the provider type is not supported.
+ */
+export function createDnsProvider(
+  type: TDnsProviderType,
+  credentials: TDnsProviderCredentials,
+): IDnsProviderClient {
+  switch (type) {
+    case 'cloudflare': {
+      if (credentials.type !== 'cloudflare') {
+        throw new Error(
+          `createDnsProvider: type mismatch — provider type is 'cloudflare' but credentials.type is '${credentials.type}'`,
+        );
+      }
+      return new CloudflareDnsProvider(credentials.apiToken);
+    }
+    default: {
+      const _exhaustive: never = type;
+      throw new Error(`createDnsProvider: unsupported provider type: ${_exhaustive}`);
+    }
+  }
+}