feat: initial backend scaffolding

migrating away from convex

Co-authored-by: Ona <no-reply@ona.com>

apps/backend/internal/database/postgres.go

@@ -0,0 +1,15 @@
+package database
+
+import (
+	"database/sql"
+
+	"github.com/uptrace/bun"
+	"github.com/uptrace/bun/dialect/pgdialect"
+	"github.com/uptrace/bun/driver/pgdriver"
+)
+
+func NewFromPostgres(url string) *bun.DB {
+	sqldb := sql.OpenDB(pgdriver.NewConnector(pgdriver.WithDSN(url)))
+	db := bun.NewDB(sqldb, pgdialect.New())
+	return db
+}