api_google_nano_banana2_image_edit references removed node GeminiNanoBanana2V2 (also widget order mismatch)

## Bug: `api_google_nano_banana2_image_edit` template references removed node `GeminiNanoBanana2V2`

The template `templates/api_google_nano_banana2_image_edit.json` contains a node of type **`GeminiNanoBanana2V2`**, but the only node currently installed on Comfy Cloud is **`GeminiNanoBanana2`** (no `V2` suffix), with a different widget signature.

This is a top-30 template by usage (7,847 runs per the cloud `search_templates` listing) and currently fails on cloud with:
```
Workflow validation failed — unknown node type(s): "GeminiNanoBanana2V2"
```

### Reproduction

```bash
curl -sS -L https://raw.githubusercontent.com/Comfy-Org/workflow_templates/main/templates/api_google_nano_banana2_image_edit.json \
| python3 -c "import json,sys; d=json.load(sys.stdin); print({n.get('type') for n in d['nodes']})"
# {'GeminiNanoBanana2V2', 'LoadImage', 'SaveImage'}
```

vs. cloud's installed node (via the comfyui-cloud MCP `search_nodes` tool):
```json
{"name": "GeminiNanoBanana2", "display_name": "Nano Banana 2", "category": "api node/image/Gemini", ...}
```

### Note: also a parameter-shape mismatch, not just a name mismatch

Renaming `GeminiNanoBanana2V2` → `GeminiNanoBanana2` is **not** sufficient. The template's `widgets_values` use the old V2 schema; the current `GeminiNanoBanana2` schema is different:

Current `GeminiNanoBanana2` required widget order:
```
prompt, model, seed, aspect_ratio, resolution, response_modalities, thinking_level
```

After patching node type only, cloud rejects with:
```
"value_not_in_list" — aspect_ratio = "MINIMAL" (was meant for thinking_level)
"value_not_in_list" — response_modalities = "randomize" (control_after_generate value)
"value_not_in_list" — thinking_level = "IMAGE" (was meant for response_modalities)
```

So the template's `widgets_values` array is also in the old V2 order and needs to be re-mapped, **or** the `V2` variant of the node needs to be reinstated on cloud.

### Suggested fix

Either:
1. Republish the template using the current `GeminiNanoBanana2` node + correct widget order, **or**
2. Restore `GeminiNanoBanana2V2` as a still-installed compatibility alias on cloud.

### Discovered during

`comfy_cloud` MCP smoke test round R001-popular-2026-05-11 (test-02-template-workflow-execution).