add child-model agent_task flow with node model capability and stricter device contracts

pkg/nodes/manager.go

@@ -137,6 +137,8 @@ func (m *Manager) SupportsAction(nodeID, action string) bool {
 	switch action {
 	case "run":
 		return n.Capabilities.Run
+	case "agent_task":
+		return n.Capabilities.Model
 	case "camera_snap", "camera_clip":
 		return n.Capabilities.Camera
 	case "screen_record", "screen_snapshot":
@@ -162,6 +164,10 @@ func (m *Manager) PickFor(action string) (NodeInfo, bool) {
 			if n.Capabilities.Run {
 				return n, true
 			}
+		case "agent_task":
+			if n.Capabilities.Model {
+				return n, true
+			}
 		case "camera_snap", "camera_clip":
 			if n.Capabilities.Camera {
 				return n, true

pkg/nodes/transport.go

@@ -75,6 +75,8 @@ func actionHTTPPath(action string) string {
 		return "/run"
 	case "invoke":
 		return "/invoke"
+	case "agent_task":
+		return "/agent/task"
 	case "camera_snap":
 		return "/camera/snap"
 	case "camera_clip":

pkg/nodes/types.go

@@ -6,6 +6,7 @@ import "time"
 type Capabilities struct {
 	Run      bool `json:"run"`
 	Invoke   bool `json:"invoke"`
+	Model    bool `json:"model"`
 	Camera   bool `json:"camera"`
 	Screen   bool `json:"screen"`
 	Location bool `json:"location"`
@@ -23,6 +24,7 @@ type NodeInfo struct {
 	Token        string       `json:"token,omitempty"`
 	Capabilities Capabilities `json:"capabilities"`
 	Actions      []string     `json:"actions,omitempty"`
+	Models       []string     `json:"models,omitempty"`
 	RegisteredAt time.Time    `json:"registered_at,omitempty"`
 	LastSeenAt   time.Time    `json:"last_seen_at"`
 	Online       bool         `json:"online"`
@@ -32,6 +34,8 @@ type NodeInfo struct {
 type Request struct {
 	Action string                 `json:"action"`
 	Node   string                 `json:"node,omitempty"`
+	Task   string                 `json:"task,omitempty"`
+	Model  string                 `json:"model,omitempty"`
 	Args   map[string]interface{} `json:"args,omitempty"`
 }