feat(music): persist live playback state to postgres

The queue and now-playing state only ever lived in the bot's memory,
so the dashboard had nothing real to show and a restart silently
wiped whatever was queued. Adds a musicrepo package and a syncState
call after every queue-changing action (play, skip, pause, volume,
stop, track end) that mirrors the current track and queue into
music_now_playing and music_queue.

No user-visible change yet, this is groundwork for the dashboard
queue/now-playing view.

internal/bot/bot.go

@@ -3,6 +3,7 @@ package bot
 import (
 	"log"
 	"velox-bot/internal/commands"
+	"velox-bot/internal/db/repos/musicrepo"
 	"velox-bot/internal/db/services"
 	"velox-bot/internal/events"
 	"velox-bot/internal/music"
@@ -17,11 +18,12 @@ type Bot struct {
 	Commands           []*discordgo.ApplicationCommand
 	registeredCommands []*discordgo.ApplicationCommand
 	Services           *services.Services
+	MusicRepo          *musicrepo.Repo
 	LavalinkHost       string
 	LavalinkPass       string
 }
 
-func NewBot(token, appID, guildID, lavalinkHost, lavalinkPass string, cmds []*discordgo.ApplicationCommand, services *services.Services) (*Bot, error) {
+func NewBot(token, appID, guildID, lavalinkHost, lavalinkPass string, cmds []*discordgo.ApplicationCommand, services *services.Services, musicRepo *musicrepo.Repo) (*Bot, error) {
 	session, err := discordgo.New("Bot " + token)
 	if err != nil {
 		return nil, err
@@ -46,6 +48,7 @@ func NewBot(token, appID, guildID, lavalinkHost, lavalinkPass string, cmds []*di
 		GuildID:      guildID,
 		Commands:     cmds,
 		Services:     services,
+		MusicRepo:    musicRepo,
 		LavalinkHost: lavalinkHost,
 		LavalinkPass: lavalinkPass,
 	}, nil
@@ -56,7 +59,7 @@ func (b *Bot) Start() error {
 		return err
 	}
 
-	_ = music.Init(b.Session, b.AppID, b.LavalinkHost, b.LavalinkPass)
+	_ = music.Init(b.Session, b.MusicRepo, b.AppID, b.LavalinkHost, b.LavalinkPass)
 
 	b.registeredCommands = make([]*discordgo.ApplicationCommand, len(b.Commands))
 	for _, cmd := range b.Commands {