Polygres SDK 0.4.0

Added

• Added pgContext 0.2.0-aligned names for vector and filter registration,
  collection deletion, point scrolling, facets, and dense plus full-text
  queries.
• Added a frozen SDK 0.3.0 method-contract baseline for compatibility checks.
• Added a pinned, CI-checked pgContext 0.2.0 compatibility inventory that
  records aligned, managed, safely partial, SQL-only, deferred privileged, and
  experimental items with no ambiguous missing stable signatures.
• Added typed collection aliases, limits, vector configuration, bulk points,
  payload mutation, candidate and raw-vector search, recommendation,
  discovery, exploration, query-plan builders and execution, index
  diagnostics, collection telemetry, query statistics, model versions, and
  embedding migrations.
• Added additive pgContext compatibility counts to Context capabilities.

Compatibility

• Existing SDK 0.3.0 method names remain available with unchanged signatures,
  HTTP requests, response types, exceptions, idempotency, and retry behavior.
• Aligned names delegate silently to the existing SDK 0.3.0 implementations.
  Upgrading without changing application code does not select new behavior.

Changed

• Added synchronized-project mode handling: connection_info() raises
  PolygresPermissionError with SYNCED_PROJECT_SURFACE_UNAVAILABLE while
  readiness, vector, hybrid, graph, text-search, and pgContext stay available.