Regression in StaticSitesClient 20260720.247.2: Next.js hybrid deployments fail with "Failed to deploy the Azure Functions" (worked on 20260714.240.1)

## Summary

Since the StaticSitesClient rolled from `20260714.240.1` to `20260720.247.2` (~2026-07-21 → 2026-07-27 in our deployments), **every deployment of our Next.js hybrid app fails** with:

```
Status: Failed. Time: 33.0460794(s)
Deployment Failed :(
Deployment Failure Reason: Failed to deploy the Azure Functions.
```

The failure is **server-side, after a successful artifact upload** ("Finished Upload. Polling on deployment." → Failed at ~33s), on two independent Static Web Apps resources (staging + production, separate subscriptions). The identical application code deployed successfully on 2026-07-21 with client `20260714.240.1`.

## Evidence it is not application-side

We reproduced the failure 5 times across every variable we control:

| Attempt | App state | Result |
|---|---|---|
| 2026-07-21 | Next 16.2.6 | ✅ success (client 20260714.240.1) |
| 2026-07-27 #1 | Next 16.2.12 | ❌ (client 20260720.247.2) |
| 2026-07-27 #2 | Next 16.2.12, `sharp`/`@img` excluded via `outputFileTracingExcludes` (rules out bundle size) | ❌ |
| 2026-07-27 #3 | **Reverted to Next 16.2.6** — near-identical to the last green deploy | ❌ |
| 2026-07-27 #4 | Next 16.2.6 + `staticwebapp.config.json` `platform.apiRuntime: node:20` | ❌ |

The only delta between the last success and the failures is the deployment client version printed in the action logs.

## Environment

- GitHub Actions, `Azure/static-web-apps-deploy@v1`, prebuilt app (`skip_app_build: true`), Next.js hybrid (App Router, ISR + server rendering), output `.next`
- Node warning in logs: "Defaulting to version: 22" (identical in the last successful run)
- Log excerpt (identical shape in all failures): `Detected the following framework: Next.js` → `Repackaged Next.js app to deploy on the backend` → `Zipping Api Artifacts` → upload OK → poll → `Failed to deploy the Azure Functions`

## Ask

1. Was there a change in the Next.js repackaging / functions provisioning path in `20260720.247.2`?
2. Is there a supported way to **pin the deployment client version** in the GitHub Action as a mitigation?

Deployment IDs available on request (e.g. `32541b25-d739-419a-8fcc-62ddaadeb7a3`, 2026-07-27). Happy to provide full logs privately.

Start with Azure/static-web-apps-deploy@v1 and compare deployment logs for client versions 20260714.240.1 and 20260720.247.2, including the available deployment IDs. Check the Next.js repackaging, Azure Functions provisioning, and staticwebapp.config.json path; done means identifying the regression and documenting whether client-version pinning is supported.

Written by the indexing model from the issue text.