[labkey-jeckels]

Rationale

Make the Peptide Map's Excel export show each peptide of a cross-linked peptide on its own row instead of stacking values as multi-line text in a single cell, per Issue 55042. Values that describe the cross-link as a whole stay in one cell, merged across those rows, so they're still shown once.

Changes

• Peptide, Peptide Identity, and Peptide Location get one row per cross-linked peptide in the xlsx export; all other columns are merged across those rows
• Chain is split per peptide only when the peptides are on different chains, and merged otherwise
• Text columns in this export are widened to fit their longest line, since the default auto-sizing ignores merged cells and runs narrow
• The on-screen grid, TSV export, and other reports are unchanged
• Added a Selenium check of the exported workbook's rows and merged cells

Tasks

• Claude Code Review
• Manual Testing
• Test Automation
• Verify Fix