Side-by-side ruled tables still share projected text lines

Summary

After side-by-side ruled grids are identified as independent geometry components, same-y text from adjacent table rectangles can still be grouped into shared projected lines. Each ruled candidate then sees text from the other table as overhang, is rejected, and fallback emits a merged table.

The completed fix is now included directly in #392 at 26b79a6.

Public reproduction

• GitHub preview / download
• Raw PDF
• SHA-256: e9b56e7a3f1d990d9e1f1b63b46e5d89b8ce1afaa85c9e17a09d83d1f5563b8d

The PDF is a self-authored, synthetic one-page Word-to-PDF document. It has no customer, personal, credential, internal-project, or business-specific data.

Command

lit parse /input.pdf \
  --no-ocr \
  --format markdown \
  --output /results/output.md \
  --quiet

Observed pipeline before the fix

At the previous #392 head (9d740a4), geometry is already separate but text projection is not:

two independent vector grids
-> two ruled components
-> shared cross-table projected text lines
-> ruled candidates rejected for adjacent-table overhang
-> fallback emits one merged 6-column table

Expected output

## Release channels

| Channel | Status | Owner |
|---|---|---|
| Stable | Ready | Team A |
| Beta | Testing | Team B |
| Nightly | Active | Team C |

## Support windows

| Region | Window | Contact |
|---|---|---|
| East | Morning | Desk 1 |
| West | Afternoon | Desk 2 |
| Central | Evening | Desk 3 |

Fix in #392

The updated projection path receives the detected ruled-table rectangles and uses them as structural boundaries:

• same-y items owned by different table rectangles cannot become one line;
• nearby labels can belong to exactly one table;
• page-spanning labels remain unowned;
• table-owned lines are ordered left-to-right within a side-by-side band and top-to-bottom across bands;
• ordinary non-table line grouping keeps its existing y tolerance.

A/B result

Regression coverage

#392 now covers the published side-by-side shape plus:

• one wide ruled table;
• vertically stacked ruled tables;
• ordinary two-column prose;
• one spanning heading above two tables;
• multiple table bands and a non-transitive three-table overlap.

This issue should close when #392 is merged. The separate same-y Markdown heading-continuation boundary found during adjacent testing is tracked in #418.