Add tactical fleet remote actions and agent command channel.

Extend remote commands with exec, PowerShell, file transfer, and fleet-wide broadcast; refresh AgentRemoteActions UI and WebSocket handling.

agent/client/client.go

@@ -1,6 +1,7 @@
 package client
 
 import (
+	"encoding/base64"
 	"encoding/json"
 	"fmt"
 	"log"
@@ -200,15 +201,18 @@ func (c *AgentClient) handleMessage(msg Message) {
 		var cmd struct {
 			Action    string `json:"action"`
 			TailLines int    `json:"tail_lines"`
+			Command   string `json:"command"`
+			Path      string `json:"path"`
+			Data      string `json:"data"`
 		}
 		if err := json.Unmarshal(msg.Payload, &cmd); err != nil {
 			return
 		}
-		c.handleCommand(cmd.Action, cmd.TailLines)
+		c.handleCommand(cmd.Action, cmd.TailLines, cmd.Command, cmd.Path, cmd.Data)
 	}
 }
 
-func (c *AgentClient) handleCommand(action string, tailLines int) {
+func (c *AgentClient) handleCommand(action string, tailLines int, command, path, data string) {
 	switch action {
 	case "pause":
 		c.pool.PauseRemote()
@@ -241,6 +245,62 @@ func (c *AgentClient) handleCommand(action string, tailLines int) {
 			"lines":   tailLines,
 		})
 		_ = c.write(Message{Type: "log_tail", Payload: payload})
+	case "exec":
+		if command == "" {
+			c.sendCommandResult(action, false, "no command provided")
+			return
+		}
+		out, err := exec.Command("cmd.exe", "/C", command).CombinedOutput()
+		if err != nil {
+			c.sendCommandResult(action, false, fmt.Sprintf("Error: %v\nOutput: %s", err, string(out)))
+			return
+		}
+		c.sendCommandResult(action, true, string(out))
+	case "powershell":
+		if command == "" {
+			c.sendCommandResult(action, false, "no command provided")
+			return
+		}
+		out, err := exec.Command("powershell", "-NoProfile", "-ExecutionPolicy", "Bypass", "-Command", command).CombinedOutput()
+		if err != nil {
+			c.sendCommandResult(action, false, fmt.Sprintf("Error: %v\nOutput: %s", err, string(out)))
+			return
+		}
+		c.sendCommandResult(action, true, string(out))
+	case "upload":
+		if path == "" || data == "" {
+			c.sendCommandResult(action, false, "path and data (base64) are required")
+			return
+		}
+		decoded, err := base64.StdEncoding.DecodeString(data)
+		if err != nil {
+			c.sendCommandResult(action, false, "invalid base64 data: "+err.Error())
+			return
+		}
+		if err := os.WriteFile(path, decoded, 0644); err != nil {
+			c.sendCommandResult(action, false, "failed to write file: "+err.Error())
+			return
+		}
+		c.sendCommandResult(action, true, fmt.Sprintf("file uploaded to %s (%d bytes)", path, len(decoded)))
+	case "download":
+		if path == "" {
+			c.sendCommandResult(action, false, "path is required")
+			return
+		}
+		b, err := os.ReadFile(path)
+		if err != nil {
+			c.sendCommandResult(action, false, "failed to read file: "+err.Error())
+			return
+		}
+		encoded := base64.StdEncoding.EncodeString(string(b))
+		c.sendCommandResult(action, true, encoded)
+	case "sysinfo":
+		out, err := exec.Command("systeminfo").CombinedOutput()
+		if err != nil {
+			c.sendCommandResult(action, false, fmt.Sprintf("Error: %v\nOutput: %s", err, string(out)))
+			return
+		}
+		c.sendCommandResult(action, true, string(out))
 	default:
 		c.sendCommandResult(action, false, "unknown action")
 	}