Adds DatabaseExporter class that exports query results to compressed protobuf format. Supports SQL Server and Oracle providers with streaming compression and SHA256 hash verification.
Add DbExporter tool project with: - Project file targeting .NET 10 with required packages (protobuf-net-data, ZstdSharp.Port, Microsoft.Data.SqlClient, Oracle.ManagedDataAccess.Core) - ExportDefinition model for JSON-based export configuration - Placeholder Program.cs entry point