fixes

server/internal/db/db.go

@@ -2,16 +2,30 @@ package db
 
 import (
 	"context"
+	"fmt"
 	"time"
 
 	"go.mongodb.org/mongo-driver/v2/mongo"
 	"go.mongodb.org/mongo-driver/v2/mongo/options"
+	"go.mongodb.org/mongo-driver/v2/x/mongo/driver/connstring"
 )
 
 var Client *mongo.Client
 var Database *mongo.Database
 
-func Connect(uri, dbName string) error {
+// Connect resolves the database name from the URI path (e.g.
+// mongodb://host:27017/vantage), falling back to fallbackDB when the URI names
+// none, so a bare URI still works without a separate MONGO_DB env var.
+func Connect(uri, fallbackDB string) error {
+	cs, err := connstring.ParseAndValidate(uri)
+	if err != nil {
+		return fmt.Errorf("parse MONGO_URI: %w", err)
+	}
+	dbName := cs.Database
+	if dbName == "" {
+		dbName = fallbackDB
+	}
+
 	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
 	defer cancel()