Add mcp dns and mcp node routes commands

mcp dns queries MCNS via an agent to list all zones and DNS records.
mcp node routes queries mc-proxy on each node for listener/route status,
matching the mcproxyctl status output format.

New agent RPCs: ListDNSRecords, ListProxyRoutes.

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

internal/agent/dns.go

@@ -26,8 +26,8 @@ type DNSRegistrar struct {
 	logger     *slog.Logger
 }
 
-// dnsRecord is the JSON representation of an MCNS record.
-type dnsRecord struct {
+// DNSRecord is the JSON representation of an MCNS record.
+type DNSRecord struct {
 	ID    int    `json:"ID"`
 	Name  string `json:"Name"`
 	Type  string `json:"Type"`
@@ -136,8 +136,87 @@ func (d *DNSRegistrar) RemoveRecord(ctx context.Context, serviceName string) err
 	return nil
 }
 
+// DNSZone is the JSON representation of an MCNS zone.
+type DNSZone struct {
+	Name string `json:"Name"`
+}
+
+// ListZones returns all zones from MCNS.
+func (d *DNSRegistrar) ListZones(ctx context.Context) ([]DNSZone, error) {
+	if d == nil {
+		return nil, fmt.Errorf("DNS registrar not configured")
+	}
+
+	url := fmt.Sprintf("%s/v1/zones", d.serverURL)
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
+	if err != nil {
+		return nil, fmt.Errorf("create list zones request: %w", err)
+	}
+	req.Header.Set("Authorization", "Bearer "+d.token)
+
+	resp, err := d.httpClient.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("list zones: %w", err)
+	}
+	defer func() { _ = resp.Body.Close() }()
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, fmt.Errorf("read list zones response: %w", err)
+	}
+
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("list zones: mcns returned %d: %s", resp.StatusCode, string(body))
+	}
+
+	var envelope struct {
+		Zones []DNSZone `json:"zones"`
+	}
+	if err := json.Unmarshal(body, &envelope); err != nil {
+		return nil, fmt.Errorf("parse list zones response: %w", err)
+	}
+	return envelope.Zones, nil
+}
+
+// ListZoneRecords returns all records in the given zone (no filters).
+func (d *DNSRegistrar) ListZoneRecords(ctx context.Context, zone string) ([]DNSRecord, error) {
+	if d == nil {
+		return nil, fmt.Errorf("DNS registrar not configured")
+	}
+
+	url := fmt.Sprintf("%s/v1/zones/%s/records", d.serverURL, zone)
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
+	if err != nil {
+		return nil, fmt.Errorf("create list zone records request: %w", err)
+	}
+	req.Header.Set("Authorization", "Bearer "+d.token)
+
+	resp, err := d.httpClient.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("list zone records: %w", err)
+	}
+	defer func() { _ = resp.Body.Close() }()
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, fmt.Errorf("read list zone records response: %w", err)
+	}
+
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("list zone records: mcns returned %d: %s", resp.StatusCode, string(body))
+	}
+
+	var envelope struct {
+		Records []DNSRecord `json:"records"`
+	}
+	if err := json.Unmarshal(body, &envelope); err != nil {
+		return nil, fmt.Errorf("parse list zone records response: %w", err)
+	}
+	return envelope.Records, nil
+}
+
 // listRecords returns A records matching the service name in the zone.
-func (d *DNSRegistrar) listRecords(ctx context.Context, serviceName string) ([]dnsRecord, error) {
+func (d *DNSRegistrar) listRecords(ctx context.Context, serviceName string) ([]DNSRecord, error) {
 	url := fmt.Sprintf("%s/v1/zones/%s/records?name=%s&type=A", d.serverURL, d.zone, serviceName)
 	req, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
 	if err != nil {
@@ -161,7 +240,7 @@ func (d *DNSRegistrar) listRecords(ctx context.Context, serviceName string) ([]d
 	}
 
 	var envelope struct {
-		Records []dnsRecord `json:"records"`
+		Records []DNSRecord `json:"records"`
 	}
 	if err := json.Unmarshal(body, &envelope); err != nil {
 		return nil, fmt.Errorf("parse list response: %w", err)