feat(music): add a stop command

Clears the whole queue and disconnects, mirrors the existing Stop
Manager function, just wires it up to the outbox like every other
dashboard command.

internal/music/listener.go

@@ -64,6 +64,9 @@ func dispatchCommand(cmd musicrepo.MusicCommand) error {
 	case "resume":
 		return Pause(guildID, false)
 
+	case "stop":
+		return Stop(guildID)
+
 	case "set_volume":
 		var payload struct {
 			Volume int `json:"volume"`

schema.sql

@@ -170,7 +170,7 @@ CREATE TABLE IF NOT EXISTS music_queue (
 CREATE TABLE IF NOT EXISTS music_commands (
     id BIGSERIAL PRIMARY KEY,
     guild_id BIGINT NOT NULL,
-    command_type TEXT NOT NULL CHECK (command_type IN ('skip', 'pause', 'resume', 'set_volume', 'remove_track', 'reorder', 'repeat_song', 'repeat_queue', 'add_song')),
+    command_type TEXT NOT NULL CHECK (command_type IN ('skip', 'pause', 'resume', 'set_volume', 'remove_track', 'reorder', 'repeat_song', 'repeat_queue', 'add_song', 'stop')),
     payload JSONB,
     requested_by BIGINT NOT NULL,
     created_at TIMESTAMPTZ DEFAULT NOW(),