Move dotnet api into new directory

web/backend/Infrastructure/Infrastructure.Repository/Sql/DefaultSqlConnectionFactory.cs

@@ -0,0 +1,49 @@
+using System.Data.Common;
+using Microsoft.Data.SqlClient;
+using Microsoft.Extensions.Configuration;
+
+namespace Infrastructure.Repository.Sql;
+
+public class DefaultSqlConnectionFactory(IConfiguration configuration)
+    : ISqlConnectionFactory
+{
+    private readonly string _connectionString = GetConnectionString(
+        configuration
+    );
+
+    private static string GetConnectionString(IConfiguration configuration)
+    {
+        // Check for full connection string first
+        var fullConnectionString = Environment.GetEnvironmentVariable(
+            "DB_CONNECTION_STRING"
+        );
+        if (!string.IsNullOrEmpty(fullConnectionString))
+        {
+            return fullConnectionString;
+        }
+
+        // Try to build from individual environment variables (preferred method for Docker)
+        try
+        {
+            return SqlConnectionStringHelper.BuildConnectionString();
+        }
+        catch (InvalidOperationException)
+        {
+            // Fall back to configuration-based connection string if env vars are not set
+            var connString = configuration.GetConnectionString("Default");
+            if (!string.IsNullOrEmpty(connString))
+            {
+                return connString;
+            }
+
+            throw new InvalidOperationException(
+                "Database connection string not configured. Set DB_CONNECTION_STRING or DB_SERVER, DB_NAME, DB_USER, DB_PASSWORD env vars or ConnectionStrings:Default."
+            );
+        }
+    }
+
+    public DbConnection CreateConnection()
+    {
+        return new SqlConnection(_connectionString);
+    }
+}