fix(layout): add id2label to LayoutConfig and guard missing label_task_mapping

[Manitchahar]

What this PR does

Fixes two layout-mode crashes when using custom config files:

1. LayoutConfig did not declare id2label, but glmocr/layout/layout_detector.py
   reads config.id2label.

   • Added: id2label: Optional[Dict[Union[int, str], str]] = None in glmocr/config.py.

2. layout_detector.py assumed label_task_mapping is always present and called
   .items() on it.

   • Added guard in start() to fallback when missing:
     • logs a warning
     • sets label_task_mapping = {"text": list(self.id2label.values())}

Reproduction

1. Create custom config with layout enabled but without id2label and label_task_mapping.
2. Run: glmocr parse "image.png" --config custom.yaml
3. Before: AttributeError crash. After: pipeline continues safely.

Files changed

• glmocr/config.py (+1 line)
• glmocr/layout/layout_detector.py (+5 lines)

Notes

Scope is intentionally minimal (2 files only), with no behavior change unless those config fields are missing.

[Copilot]

Pull request overview

This PR fixes two layout-mode crashes when using custom config files by adding the missing id2label field to LayoutConfig and adding a guard for missing label_task_mapping in the layout detector initialization.

Changes:

• Added id2label field to LayoutConfig to prevent AttributeError when reading config.id2label
• Added guard in layout_detector.py to handle missing label_task_mapping with a sensible default fallback

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
glmocr/config.py	Adds id2label field to LayoutConfig class definition
glmocr/layout/layout_detector.py	Adds guard to handle missing label_task_mapping with default fallback to text task type

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[then3rd]

Just fyi looks like there are new upstream changes to main that removed some dependencies needed for your branch to run. I had to to add "opencv-python>=4.8.0", back to the layout requirements in pyproject.toml

[yanhuixie]

这个PR啥时候可以合并呢？这是一个比较明确的bug，我也遇到了：
python -m glmocr.server --config .\config.yml
Error: 'LayoutConfig' object has no attribute 'id2label'

[Manitchahar]

Rebased onto current upstream main, added regression tests for missing id2label / default label_task_mapping, and full pytest passes locally (124 passed, 23 skipped).