chore: restructure project into backend and frontend folders

- Move all frontend code to frontend/ directory
- Add backend/ with Go project structure (cmd, internal, pkg)
- Add docker-compose.yml for orchestration

backend/internal/db/sqlc/querier.go

@@ -0,0 +1,21 @@
+// Code generated by sqlc. DO NOT EDIT.
+// versions:
+//   sqlc v1.30.0
+
+package db
+
+import (
+	"context"
+
+	"github.com/jackc/pgx/v5/pgtype"
+)
+
+type Querier interface {
+	CreateDelivery(ctx context.Context, arg CreateDeliveryParams) (Delivery, error)
+	DeleteDelivery(ctx context.Context, id pgtype.UUID) error
+	GetDeliveriesByDate(ctx context.Context, date pgtype.Date) ([]Delivery, error)
+	GetDeliveryByID(ctx context.Context, id pgtype.UUID) (Delivery, error)
+	UpdateDelivery(ctx context.Context, arg UpdateDeliveryParams) error
+}
+
+var _ Querier = (*Queries)(nil)