Add environment config loading and logging setup

internal/config/config.go

@@ -0,0 +1,50 @@
+package config
+
+import (
+	"errors"
+	"os"
+)
+
+type Config struct {
+	DiscordToken     string
+	LavalinkNodeName string
+	LavalinkAddress  string
+	LavalinkPassword string
+	LavalinkSecure   bool
+	Debug            bool
+}
+
+func Load() (Config, error) {
+	token := os.Getenv("DISCORD_TOKEN")
+	if token == "" {
+		return Config{}, errors.New("DISCORD_TOKEN environment variable is required")
+	}
+
+	address := os.Getenv("LAVALINK_ADDRESS")
+	if address == "" {
+		return Config{}, errors.New("LAVALINK_ADDRESS environment variable is required")
+	}
+
+	password := os.Getenv("LAVALINK_PASSWORD")
+	if password == "" {
+		return Config{}, errors.New("LAVALINK_PASSWORD environment variable is required")
+	}
+
+	cfg := Config{
+		DiscordToken:     token,
+		LavalinkNodeName: envOrDefault("LAVALINK_NODE_NAME", "main"),
+		LavalinkAddress:  address,
+		LavalinkPassword: password,
+		LavalinkSecure:   os.Getenv("LAVALINK_SECURE") == "true",
+		Debug:            os.Getenv("DEBUG") == "true",
+	}
+
+	return cfg, nil
+}
+
+func envOrDefault(key, fallback string) string {
+	if value := os.Getenv(key); value != "" {
+		return value
+	}
+	return fallback
+}