#618 @swamp/aws/cloudformation: expose StackSet instances, drift, and operations (Cloud Control cannot)

Problem

@swamp/aws/cloudformation/stack-set wraps the AWS Cloud Control API, so its methods (create / get / update / delete / sync) only return the StackSet resource (configuration + template). Cloud Control does not expose the operational surface operators actually need to reason about a StackSet:

• per-stack-instance deployment status — CURRENT / OUTDATED / INOPERABLE, detailed status, status reason (ListStackInstances)
• drift — DetectStackSetDrift, StackSetDriftDetectionDetails, and per-instance DriftStatus
• operation history — ListStackSetOperations / DescribeStackSetOperation

So with the official extension alone you cannot answer the most common StackSet questions: is it deployed across all targeted accounts/regions, does it have drift, is it safe to reapply, and why did a deployment fail.

Evidence

swamp model type describe @swamp/aws/cloudformation/stack-set --json lists only the five Cloud Control CRUD methods. None surface instances, drift, or operations, because the underlying AWS::CloudFormation::StackSet Cloud Control resource does not carry them.

Proposed solution

Add native-CloudFormation-backed read access to the cloudformation extension (Cloud Control structurally cannot provide this). Either:

• additional read methods on the stack-set type — e.g. listInstances, detectDrift (start + poll the operation), listOperations; or
• companion models — e.g. stack-set-instance, stack-set-operation — backed by @aws-sdk/client-cloudformation.

A per-instance shape carrying account, region, status, statusReason, driftStatus, and stackId is enough to answer the questions above.

Alternatives considered

• A custom standalone model over @aws-sdk/client-cloudformation (works, but every operator has to rebuild what the official extension could ship).
• Shelling out to the AWS CLI (discouraged by the model guidance).

Environment

swamp 20260608.234005.0-sha.ed5f78a4; extension @swamp/aws/cloudformation.

Upstream repository: https://github.com/swamp-club/swamp-extensions

Environment

• Extension: @swamp/aws/cloudformation@2026.06.08.2
• swamp: 20260608.234005.0-sha.ed5f78a4
• OS: darwin (aarch64)
• Deno: 2.8.2
• Shell: /bin/zsh