Bound connector source previews

README.md

@@ -17,7 +17,9 @@ or reporting behavior.
 The first executable connector capability provides tenant-isolated tabular
 origins. Operators can import bounded JSON or CSV snapshots, inspect inferred
 schemas, and expose immutable source references and content fingerprints
-through `connectors.datasource_origins@0.1.0`.
+through `connectors.datasource_origins@0.1.0`. Preview reads enforce provider
+ceilings for rows, serialized bytes, and elapsed time and report the effective
+limits and any truncation as structured diagnostics.
 
 Connectors owns acquisition, connection profiles, credentials, discovery, and
 provider health. `govoplan-datasources` registers an origin as a governed live
@@ -25,6 +27,12 @@ or cached datasource and owns staging, materializations, frozen states, and
 consumer access. Dataflow consumes that Datasources contract and never imports
 connector implementations or stores connector credentials.
 
+Each origin declares whether it is live, cached, file-backed, or static, its
+structured health state, and which projection, filter, aggregation, sorting,
+and pagination operations it can push down. The immutable snapshot provider
+currently supports projection and pagination only; consumers must keep other
+operations in Dataflow rather than assuming transport-side execution.
+
 Database, REST/HTTP, directory, managed-file, and warehouse providers can
 implement the same origin contract without changing Datasources or Dataflow.