fix(cli): make --service-url required, remove default

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

cmd/soundtouch-cli/common.go

@@ -22,10 +22,10 @@ import (
 // CloudCommonFlags defines flags for commands that talk to the AfterTouch service.
 var CloudCommonFlags = []cli.Flag{
 	&cli.StringFlag{
-		Name:    "service-url",
-		Usage:   "AfterTouch service URL",
-		Value:   "http://aftertouch.local:8000",
-		EnvVars: []string{"AFTERTOUCH_URL"},
+		Name:     "service-url",
+		Usage:    "AfterTouch service URL",
+		Required: true,
+		EnvVars:  []string{"AFTERTOUCH_URL"},
 	},
 }