Spatial attribute support

[ArnabChatterjee20k]

Summary by CodeRabbit

• New Features

  • Full spatial support: Point/LineString/Polygon types, validator, WKT encode/decode, spatial queries/operators, spatial index handling, adapter capability flags, Postgres/PostGIS initialization.

• Tests

  • Comprehensive end-to-end spatial test suite covering types, indexes, relationships, complex shapes, query combinations, and bulk operations.

• Refactor

  • Collection APIs migrated to Document-centric calls; createAttribute gained a required flag; new spatial query constants/methods added.

• Chores

  • Docker: Postgres switched to local build with PostGIS and POSTGRES_DB default set to root.