#493 workflow approve/resume cannot find suspended run when using S3 datastore

Description

When a workflow containing a manual_approval task type step is run with an S3 datastore configured, the run suspends correctly but cannot be approved or resumed. The approval-related commands (workflow approve, workflow resume, workflow approvals) all report "No suspended runs found" despite workflow run search --status suspended returning the run.

Steps to Reproduce

1. Initialize a repo with S3 datastore:

   swamp datastore setup extension @swamp/s3-datastore \
     --config '{"bucket": "my-bucket", "prefix": "my-prefix", "region": "us-east-1"}'

2. Create a workflow with a manual_approval step:

   jobs:
     - name: scan
       steps:
         - name: do-something
           task:
             type: model_method
             modelIdOrName: my-model
             methodName: get
             inputs: { identifier: "..." }
     - name: approve
       steps:
         - name: review-gate
           task:
             type: manual_approval
             prompt: "Review before proceeding"
       dependsOn:
         - job: scan
           condition: { type: succeeded }

3. Run the workflow:

   swamp workflow run my-workflow --json

   Output shows "status": "suspended" with a run ID.

4. Attempt to approve:

   swamp workflow approve my-workflow review-gate

   Fails: "No suspended runs found for workflow"

5. Try with explicit --run ID:

   swamp workflow approve my-workflow review-gate --run <run-id>

   Fails: "Workflow run not found: "

Observed Behavior

• swamp workflow run search --status suspended → finds the run correctly
• swamp workflow history get <name> → shows run with "runId": null
• swamp workflow approvals → returns empty {"approvals": []}
• swamp workflow approve → "No suspended runs found"
• swamp workflow resume → "No suspended runs found"
• Local .swamp/workflow-runs/<id>/ contains only a .log file, no state file

The approve command logs show it syncing from the S3 datastore before lookup:

INF datastore·lock Acquiring lock for "__global__"
INF datastore·sync Syncing from "@swamp/s3-datastore"...
INF datastore·sync "@swamp/s3-datastore" sync complete, already up to date

Expected Behavior

swamp workflow approve should find and approve the suspended run.

Hypothesis

The workflow run state is not being persisted to the S3 datastore (or is persisted in a location the approve/resume commands don't check). The run is indexed for search purposes but the full state needed by the approval machinery is missing.

Environment

• swamp version: 20260530.005533.0-sha.1c117111
• OS: macOS Darwin 24.6.0 (darwin-aarch64)
• Datastore: @swamp/s3-datastore v2026.05.26.1
• Extension tested with: @swamp/aws/s3 v2026.05.27.1