fix(super-converter): add tableHeader export handler

[caio-pizzol]

No description provided.

[linear]

SD-1709 Missing tableHeader export handler corrupts table exports

[github-actions]

Based on my analysis of the code and knowledge of the ECMA-376 specification, I'll now provide a review:

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Status: PASS

This PR implements formatting improvements and adds support for routing tableHeader nodes through the same translator as tableCell nodes. The OOXML handlers are spec-compliant.

Analysis

Changes Reviewed

1. tr-translator.js (line 24-26): Valid w:tr attributes

   • w:rsidDel, w:rsidR, w:rsidRPr, w:rsidTr - These are valid revision ID attributes per ECMA-376 §17.13.5
   • w14:paraId, w14:textId - Valid Office 2010 extended attributes per ECMA-376 Part 4

2. tableHeader routing (exporter.js): Both tableHeader and tableCell map to w:tc

   • This is correct - OOXML has no separate element for header cells
   • Headers are typically distinguished via styling/conditional formatting, not element type
   • See w:tc specification

3. tr-helpers.js (line 85-103): Placeholder cell detection logic

   • Code formatting improvements only (added braces for clarity)
   • Logic is unchanged and doesn't affect OOXML output

4. gridBefore/gridAfter handling:

   • Correctly uses w:gridBefore and w:gridAfter from w:trPr per ECMA-376 §17.4.14-15
   • These elements indicate blank grid columns before/after cells in a row
   • Implementation correctly strips placeholder cells during export (decode function)

Spec Compliance Notes

• All XML attributes declared in validXmlAttributes exist in ECMA-376
• The handlers correctly process w:trPr (table row properties) per §17.4.82
• No required attributes are missing (w:tr has no required attributes)
• Default value handling follows spec conventions

The implementation demonstrates proper understanding of OOXML table structure where header semantics are handled through styling rather than distinct element types.