Polygres SDK 0.2.0

Added

• Added the project.context namespace for pgContext collection, point, search, migration, and operation workflows.
• Added PolygresVersionWarning and PolygresMaintenanceError.

Changed

• Retired vector-config operations now raise PolygresValidationError with pgContext migration guidance.

Fixed

• Corrected vector metric handling and configured ID-type behavior.
• Improved validation and runtime error messages.
• Restored Python 3.10 compatibility.