Granite Docling extract images with higher resolution

### Bug

Using granite docling, I can't extract images with a good resolution.

### Steps to reproduce

Wrote a simple script that works on page 5 only of https://arxiv.org/pdf/2501.17887:
```
from pathlib import Path
from docling.document_converter import DocumentConverter
from docling.datamodel.base_models import InputFormat
from docling.document_converter import PdfFormatOption
from docling_core.types.doc import ImageRefMode
from docling.datamodel.pipeline_options import VlmPipelineOptions
from docling.pipeline.vlm_pipeline import VlmPipeline
from docling.datamodel.vlm_model_specs import GRANITEDOCLING_TRANSFORMERS as granite_docling_vlm_conversion_options

output_dir = Path("output")
output_dir.mkdir(exist_ok=True)

docling_paper = "arvix.pdf" # Only page 5 of https://arxiv.org/pdf/2501.17887

vlm_options = granite_docling_vlm_conversion_options
IMAGE_RESOLUTION_SCALE = 1.0

vlm_pipeline_options = VlmPipelineOptions(
force_backend_text=False,
vlm_options=vlm_options,
images_scale=IMAGE_RESOLUTION_SCALE,
generate_picture_images=True
)

converter_vlm = DocumentConverter(
format_options={
InputFormat.PDF: PdfFormatOption(
pipeline_options=vlm_pipeline_options,
pipeline_cls=VlmPipeline,
)
}
)

vlm_result = converter_vlm.convert(docling_paper)
vlm_doc = vlm_result.document
html_filename = output_dir / f"{docling_paper}.html"
vlm_doc.save_as_html(html_filename, image_mode=ImageRefMode.REFERENCED)
```

With this, the images are low resolution (on top on being badly framed):

When pushing `IMAGE_RESOLUTION_SCALE` to `2.0`, then we see this bug where the images are extracted from somewhere else in the document it looks like:

### Docling version

```
2025-10-09 11:24:55,555 - INFO - Loading plugin 'docling_defaults'
2025-10-09 11:24:55,560 - INFO - Registered ocr engines: ['easyocr', 'ocrmac', 'rapidocr', 'tesserocr', 'tesseract']
Docling version: 2.55.1
Docling Core version: 2.48.4
Docling IBM Models version: 3.9.1
Docling Parse version: 4.5.0
Python: cpython-311 (3.11.10)
Platform: macOS-15.7.1-x86_64-i386-64bit
```

### Python version

```
Python 3.11.10
```