feat: add shared probe entity types (Config, Result)

internal/entities/probe/probe.go

@@ -0,0 +1,29 @@
+package probe
+
+import "fmt"
+
+// Config defines a network probe task sent from hub to agent.
+type Config struct {
+	Target   string `cbor:"0,keyasint" json:"target"`
+	Protocol string `cbor:"1,keyasint" json:"protocol"` // "icmp", "tcp", or "http"
+	Port     uint16 `cbor:"2,keyasint,omitempty" json:"port,omitempty"`
+	Interval uint16 `cbor:"3,keyasint" json:"interval"` // seconds
+}
+
+// Result holds aggregated probe results for a single target.
+type Result struct {
+	AvgMs float64 `cbor:"0,keyasint" json:"avg"`
+	MinMs float64 `cbor:"1,keyasint" json:"min"`
+	MaxMs float64 `cbor:"2,keyasint" json:"max"`
+	Loss  float64 `cbor:"3,keyasint" json:"loss"` // packet loss %
+}
+
+// Key returns the map key used for this probe config (e.g. "icmp:1.1.1.1", "tcp:host:443", "http:https://example.com").
+func (c Config) Key() string {
+	switch c.Protocol {
+	case "tcp":
+		return c.Protocol + ":" + c.Target + ":" + fmt.Sprintf("%d", c.Port)
+	default:
+		return c.Protocol + ":" + c.Target
+	}
+}