fix(docx): let the list's own block carry its spacing

[developer0hye]

Summary

• emit one block per list, carrying both the Word line box and the list's w:spacing edge gaps
• generate_list takes the line-height settings instead of a bool and builds the wrapper itself

Related issue

Fixes #463

Details

A list was wrapped in two blocks: an outer one holding the Word line box, and an inner one holding the edge gaps. Typst does not apply block spacing at a container's edges, so the inner gaps never reached the boundary and the outer wrapper — which set neither above nor below — fell back to Typst's own 1.2em block.spacing.

Baseline-to-baseline pitch from a numbered item to the shaded code line after it, page 1:

Boundary	Word GT	before	after
item 1 to $ office2pdf report.docx	15.64 pt	25.83 pt	15.64 pt
item 2 to $ office2pdf slides.pptx …	15.64 pt	25.83 pt	15.64 pt
item 3 to $ office2pdf *.xlsx …	15.64 pt	25.83 pt	15.64 pt

Mean absolute vertical drift on that file falls from 12.67pt to 1.43pt, and across the business corpus from 13.52pt to 12.88pt.

02_contract_ko moves the other way, 4.20pt to 9.11pt. That is the leaked default having masked a deficit rather than helped: its w:spacing w:after there really is 4pt, matching Word's 22.32pt pitch against an 18pt line box, and the ~8pt the document is short by accumulates earlier — its first three paragraphs are already 2.79pt, 7.52pt, and 7.76pt high before any list appears, which is the title-paragraph defect #402 tracks.

Testing

• cargo fmt --all -- --check
• cargo test --workspace
• cargo clippy --workspace --all-targets --all-features
• python3 scripts/validate_business_golden_mocks.py
• pdftotext -bbox pitch comparison against all 10 Word-produced DOCX golden PDFs
• pdftoppm -r 150 rendering, matched region crops, and magick compare -metric AE -fuzz 5%

Visual impact

• No rendered PDF change
• Rendered PDF change or visual evidence added
• Reason: the gap between a list and its neighbours changed on every DOCX with a list.

Visual audit

• Issue: DOCX: list blocks inherit Typst's default block spacing instead of w:spacing #463
• Fixture: tests/golden_mocks/business/sources/docx/05_technical_manual_en.docx
• Page(s): page 1 of the Word GT and of the office2pdf output
• Renderer and DPI: pdftoppm, 150 DPI
• Evidence mode: fix
• New follow-up issues found in this audit: None
• GT: assets/bugfixes/issue-463/gt.jpg
• Before: assets/bugfixes/issue-463/before.jpg
• After: assets/bugfixes/issue-463/after.jpg

Visual comparison

GT	Before	After

Required inspection

• Rendered all evidence at 150 DPI or higher
• Stored progressive JPEG quality 86 assets with metadata stripped
• Inspected matched region crops at full resolution
• Ran the 5% fuzz pixel-difference sweep
• Inventoried hairlines and border dash styles
• Inventoried font weight, italic, and underline emphasis

The 5% fuzz sweep against the size-normalized GT falls from 88,314 to 57,544 differing pixels. The residual clusters are the 12pt code-paragraph indent tracked in #464 plus font antialiasing. The page's only hairline is the header rule, which matches GT in position, width, and weight on the full-resolution crop; there are no dashed or dotted borders. Bold headings, the monospace runs, and the italic disclaimer all keep the same emphasis as GT.

Deviation audit

Check	Result
Page count/order	Matches GT - two pages in the same order
Element presence	Matches GT - every heading, paragraph, command line, and the exit-code table are present
Position/size	Remaining: #464 - the shaded command paragraphs still lose their 12pt w:ind w:left; the page box and text column match GT
Rotation/flip	No deviation observed - the fixture contains no rotated or flipped elements
Fill	Matches GT - the F4F4F4 code shading is the same color, though its left edge inherits #464
Stroke/border	No deviation observed - the header rule matches GT and there are no other strokes
Text content	Matches GT - all strings on both pages are preserved
Font family/weight/style	Matches GT - Arial body, Courier New code, bold headings, and the italic disclaimer all match
Text color	Matches GT - the navy headings, grey header, and black body all match
Alignment	Matches GT - the justified body paragraphs and centered footer match
Line/paragraph spacing	Fixed - every list-to-code pitch is now Word's 15.64pt against the previous 25.83pt, and the file's mean absolute drift falls from 12.67pt to 1.43pt
Clipping/overflow	No deviation observed - no glyph is clipped and nothing overflows the text column

Checklist

• Commits include a Signed-off-by line
• PR scope contains one root cause
• Remaining visual deviations each reference an open issue