fix(docx): style PAGE and NUMPAGES fields from their run

[developer0hye]

Summary

• Carry the containing run's TextStyle on the PAGE and NUMPAGES field IR variants and render the counter under those properties.
• Word applies the run's properties to a field result; office2pdf fell back to the document default, printing the number at roughly 11 pt black inside an 8 pt gray footer and inflating the line box.

Related issue

Fixes #450

Testing

• cargo test --workspace (1832 tests, all pass)
• cargo clippy --workspace --all-targets (clean)
• cargo fmt --check
• pdftotext -bbox on the page-1 footer of 05_technical_manual_en against the Word PDF
• pdftoppm -r 150 plus a 300% crop of the footer line
• magick compare -metric AE -fuzz 5% on the size-normalized page

Page-1 footer glyph boxes:

Glyph	Word GT	before	after
- literal	797.55-806.40	800.68-808.18	798.99-806.50
1 field	797.55-806.40	796.67-809.21	798.99-806.50

In Word every glyph on the footer line shares one box. Before the fix the field's box was 12.54 pt against the literals' 7.51 pt; after, all three match.

Visual impact

• No rendered PDF change
• Rendered PDF change or visual evidence added
• Reason:

Visual audit

• Issue: DOCX: PAGE and NUMPAGES fields in headers/footers lose their run formatting #450
• Fixture: tests/golden_mocks/business/sources/docx/05_technical_manual_en.docx
• Page(s): 1 (page 2 carries the same footer and was also checked)
• Renderer and DPI: pdftoppm, 150 DPI
• Evidence mode: fix
• New follow-up issues found in this audit: None
• GT: assets/bugfixes/issue-450/gt.jpg
• Before: assets/bugfixes/issue-450/before.jpg
• After: assets/bugfixes/issue-450/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

Deviation audit

Check	Result
Page count/order	Matches GT: two pages in the same order
Element presence	Matches GT: header, header rule, headings, code blocks, and footer are all present
Position/size	Fixed: the footer field now shares the literals' line box instead of standing 5 pt taller
Rotation/flip	No deviation observed
Fill	Matches GT: the F4F4F4 code-block shading is present
Stroke/border	Matches GT: the 0.5 pt CCCCCC header rule is present at its w:space offset
Text content	Matches GT
Font family/weight/style	Fixed: the page number renders at the run's 8 pt instead of the document default
Text color	Fixed: the page number renders in the run's 888888 instead of black
Alignment	Matches GT: the footer stays centered
Line/paragraph spacing	Remaining: #452 tracks consecutive Courier New paragraphs advancing tighter than Word
Clipping/overflow	No deviation observed

Checklist

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