wrangler deploy persistently fails with workflows.api.error.internal_server [code: 10001] on new Free account

## Summary

Hitting `workflows.api.error.internal_server [code: 10001]` consistently on a brand-new Free-plan Cloudflare account. Worker uploads successfully, D1 migrations apply, R2 binding resolves — only the final workflow registration step (`/accounts//workflows/`) returns 500.

This appears identical to cloudflare/workers-sdk#9110 (closed as a transient server-side incident). For this account the failure is **persistent** — every attempt over the past ~24 hours fails identically, across multiple environments and after exhausting client-side workarounds.

## Reproduction

```toml
# wrangler.toml (relevant section)
[[workflows]]
name = "review-workflow-v2"
binding = "REVIEW_WORKFLOW"
class_name = "ReviewWorkflow"
```

Failing log (GitHub Actions, ubuntu-latest, US datacenter):

```
⛅️ wrangler 4.90.1
🌀 Building list of assets...
✨ Read 59 files from the assets directory
🌀 Starting asset upload...
No updated asset files to upload. Proceeding with deployment...
Total Upload: 3390.58 KiB / gzip: 724.93 KiB
Worker Startup Time: 13 ms
Your Worker has access to the following bindings:
Binding Resource
env.REVIEW_WORKFLOW (ReviewWorkflow) Workflow
env.DB (icon-review-db) D1 Database
env.BUCKET (icon-review-files) R2 Bucket
env.BROWSER Browser Run
env.AI AI
env.ASSETS Assets
... (env vars)
Uploaded icon-review (5.99 sec)

✘ [ERROR] A request to the Cloudflare API (/accounts/***/workflows/review-workflow-v2) failed.

workflows.api.error.internal_server [code: 10001]

##[error]Process completed with exit code 1.
```

## Environment

- **Account ID**: `f8b237dd484d7d40583f0e407a46ab7f`
- **Plan**: Workers Free
- **Account age**: created 2026-05-13 (≈24 hours old at first failure)
- **Wrangler version**: 4.90.1 (also reproduced with 4.77.0 pinned)
- **Runtime**: GitHub Actions ubuntu-latest **and** macOS local with proxy
- **First failure**: 2026-05-13 ~10:00 UTC
- **Most recent failure**: 2026-05-14 02:58:35 UTC
- **Failure rate**: 100% over ~10 attempts spanning 24+ hours

## What we ruled out

- ❌ **Network / proxy** — fails identically on GitHub Actions runner with clean US network
- ❌ **API Token scope** — token has `Workers Scripts:Edit`, `D1:Edit`, `Workers R2 Storage:Edit`, `Browser Rendering:Edit`, `User Details:Read`. (Note: there is no separate `Workflows` resource in the token UI — per docs Workflows operations are covered by `Workers Scripts`.)
- ❌ **Tooling regression** — pinning to wrangler 4.77.0 reproduces the same error
- ❌ **Orphaned workflow record** — renaming the workflow to a never-before-seen name produces the same 500
- ❌ **First-deploy provisioning lag** — failures span 24+ hours

## Hypothesis

Per the resolution of cloudflare/workers-sdk#9110, this looks like an account-level Workflows control-plane bug. Could a Cloudflare engineer with access check this account's Workflows provisioning state for Account ID `f8b237dd484d7d40583f0e407a46ab7f`? Happy to run any diagnostic curl probe you'd like.

## Cross-reference

- Original issue: cloudflare/workers-sdk#9110
- Related symptom (different code 10000, auth scope): https://community.cloudflare.com/t/wrangler-deploy-workflows-10000-error/827149