fix(vcs-core): reuse resolved driver schema during exec

vcs-core/packages/core/src/vcs_core/_substrate_driver.py

@@ -1505,6 +1505,7 @@ def validate_driver_ingress(
     request: IngressRequest,
     result: DriverIngressResult,
     driver: SubstrateDriver | None = None,
+    schema: DriverSchema | None = None,
 ) -> None:
     """Three-layer validator entry point (SPI v0.1).
 
@@ -1518,7 +1519,7 @@ def validate_driver_ingress(
     _validate_generic_invariants(result)
     _validate_per_request_invariants(request, result)
     if driver is not None:
-        _validate_storage_profile_result(driver, result)
+        _validate_storage_profile_result(driver, result, schema=schema)
         driver.validate_result(request, result)
 
 
@@ -1533,9 +1534,14 @@ def validate_driver_ingress_result(result: DriverIngressResult) -> None:
     _validate_generic_invariants(result)
 
 
-def _validate_storage_profile_result(driver: SubstrateDriver, result: DriverIngressResult) -> None:
+def _validate_storage_profile_result(
+    driver: SubstrateDriver,
+    result: DriverIngressResult,
+    *,
+    schema: DriverSchema | None = None,
+) -> None:
     """Enforce the driver's declared storage profile against emitted transitions."""
-    profile = driver.describe().storage_profile
+    profile = (schema or driver.describe()).storage_profile
     for transition in result.transitions:
         path = f"transition[{transition.transition_id}]"
         if profile.shape == "json-snapshot":

vcs-core/packages/core/src/vcs_core/_vcscore_runtime.py

@@ -37,7 +37,7 @@
 )
 from vcs_core._runtime_types import ExecutionContext
 from vcs_core._schema_errors import SchemaValidationError
-from vcs_core._substrate_driver import CapabilitySet, CommandRequest, DriverContext, SubstrateDriver
+from vcs_core._substrate_driver import CapabilitySet, CommandRequest, DriverContext, DriverSchema, SubstrateDriver
 from vcs_core._world_transition_coordinator import dispatch_driver
 from vcs_core.recording import NestedParentAuthorization
 from vcs_core.types import (
@@ -803,6 +803,7 @@ def _execute_spi_driver_in_operation(
             scope=scope,
             params=params,
             capabilities=resolved.schema.capabilities,
+            schema=resolved.schema,
         )
     if isinstance(driver, ExecutionBoundDriver) and command in driver.execution_commands:
         # PD1/PD2: the driver opted into execution authority for THIS command —
@@ -824,6 +825,7 @@ def _execute_spi_driver_in_operation(
             command_param_source=command_param_source,
             execution_options=execution_options,
             capabilities=resolved.schema.capabilities,
+            schema=resolved.schema,
         )
     _reject_execution_options_for_plain_command(binding.binding_name, command, execution_options)
     params = _normalize_and_admit_driver_command_params(
@@ -865,6 +867,7 @@ def _execute_spi_driver_in_operation(
                 context,
                 CommandRequest(command=command, params=dict(params)),
                 capabilities=resolved.schema.capabilities,
+                schema=resolved.schema,
             )
             oids: tuple[str, ...] = ()
             if result.effects:
@@ -892,6 +895,7 @@ def _execute_selectable_spi_driver(
     scope: ScopeInfo,
     params: dict[str, Any],
     capabilities: CapabilitySet,
+    schema: DriverSchema,
 ) -> RecordedCommandOutcome:
     """The selectable arm of the dispatch bridge (B4b W2).
 
@@ -935,6 +939,7 @@ def _execute_selectable_spi_driver(
         context,
         CommandRequest(command=command, params=dict(params)),
         capabilities=capabilities,
+        schema=schema,
     )
     bundle = manager.create_prepared_driver_candidate_bundle(
         store_id,
@@ -1004,6 +1009,7 @@ def _execute_execution_bound_driver(
     command_param_source: CommandValueSource,
     execution_options: CommandExecutionOptions,
     capabilities: CapabilitySet,
+    schema: DriverSchema,
 ) -> RecordedCommandOutcome:
     """The reversible-transaction wrap (PD2) around an execution-bound dispatch.
 
@@ -1082,6 +1088,7 @@ def _execute_execution_bound_driver(
                 context,
                 CommandRequest(command=command, params=dict(params)),
                 capabilities=capabilities,
+                schema=schema,
                 execution=capability,
             )
     except BaseException:

vcs-core/packages/core/src/vcs_core/_world_transition_coordinator.py

@@ -16,6 +16,7 @@
     CapabilitySet,
     DriverContext,
     DriverIngressResult,
+    DriverSchema,
     EvidenceCitation,
     IngressRequest,
     ObservationDraft,
@@ -313,6 +314,7 @@ def dispatch_driver(
     request: IngressRequest,
     *,
     capabilities: CapabilitySet | None = None,
+    schema: DriverSchema | None = None,
     execution: Any | None = None,
 ) -> DriverIngressResult:
     """Validated SPI dispatch around ``driver.prepare`` / ``prepare_bound``.
@@ -341,7 +343,7 @@ def dispatch_driver(
         result = driver.prepare_bound(context, request, execution)
     else:
         result = driver.prepare(context, request)
-    validate_driver_ingress(request, result, driver)
+    validate_driver_ingress(request, result, driver, schema=schema)
     _check_active_surface_post_dispatch(driver, context.active_surface, result)
     return result
 

vcs-core/packages/core/tests/unit/test_binding_surface.py

@@ -114,17 +114,6 @@ def test_binding_surface_records_metadata_and_resolver_loads_live_driver_schema(
     assert resolver.schema("runtime") is schema
 
 
-@pytest.mark.xfail(
-    reason=(
-        "PR#4 (portable copy carrier + auto backend) regressed the resolved-binding-contract "
-        "cache: the first exec calls describe() twice and the second re-resolves instead of "
-        "hitting the cache (observed 3 calls, expected 1). Functionally harmless — results are "
-        "correct — but the caching invariant is broken. Reproduces in the public checkout "
-        "(public CI does not run the vcs-core unit suite). Tracked as shepherd-agents/shepherd#11 "
-        "and the divergence ledger known-public-bugs."
-    ),
-    strict=True,
-)
 def test_vcscore_exec_uses_cached_resolved_binding_contract_without_runtime_describe(tmp_path) -> None:
     class CountingDriver(PlainCommandDriver):
         def __init__(self) -> None: