Expose residue policy in compute steps

[intel352]

Summary

• accept task-level residue_policy in step.compute_dispatch and step.compute_map
• pass residue policy through to submitted protocol.Task while leaving provider/product authority resolution in workflow-compute
• bump workflow-compute protocol dependency and add provider-catalog residue tests
• align local wfctl validation/build metadata for this plugin repo

Verification

• GOWORK=off go test ./internal -run 'Residue|ProviderCatalog' -count=1
• GOWORK=off go test ./...
• ./scripts/check-workflow-compute-alignment.sh /Users/jon/workspace/workflow-compute
• wfctl validate --allow-no-entry-points workflow.yaml
• GOWORK=off wfctl build --config workflow.yaml --no-push --tag local
• git diff --check

TDD proof

With fix removed:
GOWORK=off go test ./internal -run 'TestDispatchStepSubmitsResiduePolicy|TestMapStepSubmitsPerTaskResiduePolicies|TestDispatchStepRejectsImplicitWorkerBoundResiduePolicy' -count=1 failed with json: unknown field "residue_policy".

With fix restored:
GOWORK=off go test ./internal -run 'TestDispatchStepSubmitsResiduePolicy|TestMapStepSubmitsPerTaskResiduePolicies|TestDispatchStepRejectsImplicitWorkerBoundResiduePolicy' -count=1 passed.