Fix ONNX node name sanitization and add ai.onnx.ml domain support

[antimora]

Pull Request Template

Checklist

• Confirmed that cargo run-checks command has been executed.
• Made sure the book is up to date with changes in this PR.

Related Issues/PRs

• Fixes bug(onnx): model created using tf2onnx panics with non-valid Ident #2878 - ONNX import fails with panic on node names containing special characters

Changes

Fixed ONNX import issues:

1. Node name sanitization: Enhanced format_name function to sanitize node names with invalid identifier characters (:, /, etc.) by replacing them with underscores
2. ONNX domain support: Added support for ai.onnx.ml domain in addition to standard ONNX domain

This allows importing ONNX models generated by tf2onnx that contain special characters in node names.

Testing

• Added unit tests covering the problematic node name from the issue and various edge cases
• Verified the original failing ONNX file now imports successfully
• All existing tests pass

[antimora]

The name sanitization is happening in burn-import instead of onnx-ir. This is simpler for now and updates existing sanitization in place related. Added a todo to come back. #3208 PR attempted to fix in onnx-ir but added up introducing new issues because some names relied on old unsanitized names thus breaking code.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 30.90%. Comparing base (fb3843e) to head (00e743d).
Report is 2 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3371      +/-   ##
==========================================
- Coverage   35.19%   30.90%   -4.29%     
==========================================
  Files         342      413      +71     
  Lines       53164    60529    +7365     
==========================================
- Hits        18712    18709       -3     
- Misses      34452    41820    +7368     

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[laggui]

Fix looks good, just a minor comment for the implementation 🙂

What's the motivation behind extending support for ai.onnx.ml domain? We would need a separate list for these ops, which I'm not sure is desirable.

[antimora]

Fix looks good, just a minor comment for the implementation 🙂

What's the motivation behind extending support for ai.onnx.ml domain? We would need a separate list for these ops, which I'm not sure is desirable.

Sorry I should have explained. TensorFlow adds this when exporting even though no ops are used. I have discovered this when testing an onnx file in #2878

[laggui]

Sorry I should have explained. TensorFlow adds this when exporting even though no ops are used.

Ahh ok I see, LGTM then!

But I think we should just accept the domain without listing the ops.

[laggui]

Thank you!