feat: añadir subcomandos upload-media y set-avatar-url en agentctl

Expone las funciones separadas de profile.go como CLI:
- agentctl upload-media <id> <path> — sube sin activar avatar
- agentctl set-avatar-url <id> <mxc://...> — activa un mxc ya subido

Complementa la refactorizacion de shell/matrix/profile.go.

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

cmd/agentctl/avatar.go

@@ -41,6 +41,63 @@ func avatarCmd() *cobra.Command {
 	}
 }
 
+func uploadMediaCmd() *cobra.Command {
+	return &cobra.Command{
+		Use:   "upload-media <agent-id> <image-path>",
+		Short: "Upload an image to Matrix media repo (does NOT set it as avatar)",
+		Args:  cobra.ExactArgs(2),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			agentID, imagePath := args[0], args[1]
+
+			cfg, err := loadMatrixCfg(agentID)
+			if err != nil {
+				return err
+			}
+
+			client, err := shellmatrix.New(cfg.Matrix)
+			if err != nil {
+				return fmt.Errorf("matrix client: %w", err)
+			}
+
+			uri, err := client.UploadMedia(context.Background(), imagePath)
+			if err != nil {
+				return err
+			}
+
+			fmt.Printf("ok    %-20s  uploaded → %s\n", agentID, uri)
+			return nil
+		},
+	}
+}
+
+func setAvatarURLCmd() *cobra.Command {
+	return &cobra.Command{
+		Use:   "set-avatar-url <agent-id> <mxc-uri>",
+		Short: "Set the bot's avatar to an already-uploaded mxc:// URI",
+		Args:  cobra.ExactArgs(2),
+		RunE: func(cmd *cobra.Command, args []string) error {
+			agentID, mxcURI := args[0], args[1]
+
+			cfg, err := loadMatrixCfg(agentID)
+			if err != nil {
+				return err
+			}
+
+			client, err := shellmatrix.New(cfg.Matrix)
+			if err != nil {
+				return fmt.Errorf("matrix client: %w", err)
+			}
+
+			if err := client.SetAvatarURL(context.Background(), mxcURI); err != nil {
+				return err
+			}
+
+			fmt.Printf("ok    %-20s  avatar-url → %s\n", agentID, mxcURI)
+			return nil
+		},
+	}
+}
+
 func displaynameCmd() *cobra.Command {
 	return &cobra.Command{
 		Use:   "displayname <agent-id> [name]",

cmd/agentctl/main.go

@@ -51,6 +51,9 @@ func main() {
 		reloadCmd(mgr),
 		removeCmd(mgr),
 		avatarCmd(),
+		uploadMediaCmd(),
+		setAvatarURLCmd(),
+		autoAvatarCmd(),
 		displaynameCmd(),
 	)