✨ Upgrade Go version to 1.23.0 and update dependencies. Introduce new application structure with Clean Architecture principles, including message processing, NATS integration, and PostgreSQL repository. Add configuration management using Koanf and structured logging with Zap. Remove legacy GraphQL integration and related files. Implement dependency injection with Google Wire.

internal/infra/postgres/db.go

@@ -0,0 +1,38 @@
+package postgres
+
+import (
+	"caatsm/internal/infra/config"
+	"context"
+	"fmt"
+	"time"
+
+	"github.com/jackc/pgx/v5/pgxpool"
+)
+
+// ProvideDB creates a PostgreSQL connection pool
+func ProvideDB(cfg *config.Config) (*pgxpool.Pool, error) {
+	ctx := context.Background()
+	
+	poolConfig, err := pgxpool.ParseConfig(cfg.Postgres.URL)
+	if err != nil {
+		return nil, fmt.Errorf("failed to parse postgres URL: %w", err)
+	}
+	
+	poolConfig.MaxConns = int32(cfg.Postgres.MaxConns)
+	poolConfig.MinConns = int32(cfg.Postgres.MinConns)
+	poolConfig.MaxConnLifetime = time.Hour
+	poolConfig.MaxConnIdleTime = time.Minute * 30
+	
+	pool, err := pgxpool.NewWithConfig(ctx, poolConfig)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create connection pool: %w", err)
+	}
+	
+	// Test connection
+	if err := pool.Ping(ctx); err != nil {
+		return nil, fmt.Errorf("failed to ping database: %w", err)
+	}
+	
+	return pool, nil
+}
+