feat: Add ICMP, DNS, and GraphQL monitor types

Add three new monitor types with full support:

- ICMP: Ping monitoring with configurable packet count, tracks packet
  loss and average RTT. Marks degraded on partial packet loss.

- DNS: DNS resolution monitoring supporting A, AAAA, CNAME, MX, and TXT
  records. Optional custom DNS server and validation of expected IPs/CNAME.

- GraphQL: GraphQL endpoint monitoring with query execution, variable
  support, error detection, and content validation.

All new monitors include retry support, response time tracking, and
integrate with existing display options (round_response_time, etc).

GraphQL monitors also support SSL certificate tracking.

1 files changed, 17 insertions, 2 deletions

diff --git a/internal/config/config.go b/internal/config/config.go
index 7ed28dd..71a9b99 100644
--- a/internal/config/config.go
+++ b/internal/config/config.go
@@ -93,6 +93,16 @@ type MonitorConfig struct {
 	UserAgent           string            `yaml:"user_agent,omitempty"` // Custom User-Agent header (default: "Kaze-Monitor/1.0")
 	Headers             map[string]string `yaml:"headers,omitempty"`
 	Body                string            `yaml:"body,omitempty"`
+	// ICMP specific fields
+	PingCount int `yaml:"ping_count,omitempty"` // Number of ICMP packets to send (default: 4)
+	// DNS specific fields
+	DNSServer     string   `yaml:"dns_server,omitempty"`     // DNS server to query (default: system resolver)
+	ExpectedIPs   []string `yaml:"expected_ips,omitempty"`   // Expected IP addresses for DNS resolution
+	ExpectedCNAME string   `yaml:"expected_cname,omitempty"` // Expected CNAME record
+	RecordType    string   `yaml:"record_type,omitempty"`    // DNS record type (A, AAAA, CNAME, MX, TXT, etc.)
+	// GraphQL specific fields
+	GraphQLQuery     string            `yaml:"graphql_query,omitempty"`     // GraphQL query to execute
+	GraphQLVariables map[string]string `yaml:"graphql_variables,omitempty"` // GraphQL query variables
 }
 
 // IncidentConfig represents an incident or maintenance
@@ -300,10 +310,15 @@ func (c *Config) validate() error {
 			}
 
 			switch monitor.Type {
-			case "http", "https", "tcp", "gemini":
+			case "http", "https", "tcp", "gemini", "icmp", "dns", "graphql":
 				// Valid types
 			default:
-				return fmt.Errorf("monitor %q has invalid type %q (must be http, https, tcp, or gemini)", monitor.Name, monitor.Type)
+				return fmt.Errorf("monitor %q has invalid type %q (must be http, https, tcp, gemini, icmp, dns, or graphql)", monitor.Name, monitor.Type)
+			}
+
+			// Type-specific validation
+			if monitor.Type == "graphql" && monitor.GraphQLQuery == "" {
+				return fmt.Errorf("monitor %q is type 'graphql' but missing required 'graphql_query' field", monitor.Name)
 			}
 		}
 	}