feat(music): add /music toggle and gate playback behind it

Music could be started and controlled with no way to turn it off for
a server. Adds a music_settings table (mirrors the same one
velox-dashboard-api's dashboard toggle reads/writes), a /music toggle
command gated to Manage Server, and checks in /play, /queue, and
/volume so they refuse to run when a server has music turned off.

internal/db/services/services.go

@@ -6,6 +6,7 @@ import (
 	"velox-bot/internal/db/services/levelsettings"
 	"velox-bot/internal/db/services/logsettings"
 	"velox-bot/internal/db/services/meeting"
+	"velox-bot/internal/db/services/musicsettings"
 	"velox-bot/internal/db/services/projects"
 	"velox-bot/internal/db/services/rps"
 	"velox-bot/internal/db/services/schedule"
@@ -26,11 +27,12 @@ type Services struct {
 	Welcome       *welcome.Service
 	DefaultRole   *defaultrole.Service
 	LogSettings   *logsettings.Service
+	MusicSettings *musicsettings.Service
 }
 
 var Global *Services
 
-func NewServices(level *level.Service, levelSettings *levelsettings.Service, meeting *meeting.Service, schedule *schedule.Service, userSettings *usersettings.Service, projects *projects.Service, rps *rps.Service, twitchSvc *twitch.Service, welcomeSvc *welcome.Service, defaultRoleSvc *defaultrole.Service, logSettingsSvc *logsettings.Service) *Services {
+func NewServices(level *level.Service, levelSettings *levelsettings.Service, meeting *meeting.Service, schedule *schedule.Service, userSettings *usersettings.Service, projects *projects.Service, rps *rps.Service, twitchSvc *twitch.Service, welcomeSvc *welcome.Service, defaultRoleSvc *defaultrole.Service, logSettingsSvc *logsettings.Service, musicSvc *musicsettings.Service) *Services {
 	s := &Services{
 		Level:         level,
 		LevelSettings: levelSettings,
@@ -43,6 +45,7 @@ func NewServices(level *level.Service, levelSettings *levelsettings.Service, mee
 		Welcome:       welcomeSvc,
 		DefaultRole:   defaultRoleSvc,
 		LogSettings:   logSettingsSvc,
+		MusicSettings: musicSvc,
 	}
 	Global = s
 	return s