feat: schema-time validation, integration tests, chunk-aware codegen docs (Phases I+J+H)

Phase I: Validate boost_recency_field exists on codec before injecting into SQL.
  Gracefully disables recency boost with console.warn if field is missing.

Phase J: Integration tests for @searchConfig and @hasChunks smart tags.
  Custom makeTestSmartTagsPlugin injects tags programmatically during schema build.
  Tests cover per-table weights, recency boost, chunk-aware queries, and validation.

Phase H: Enhance codegen docs for chunk-aware embedding tables.
  Detects VectorNearbyInput.includeChunks in TypeRegistry and adds chunk-aware
  search documentation to embedding field groups in generated docs.

Author: pyramation