…6.1)

Adds regression coverage for the spec rule that section-level w:bidi
must NOT cascade to paragraph w:jc interpretation. Section bidi affects
only section-level properties (page numbers, columns), not paragraph
alignment.

The fixture has a section with <w:bidi/> but two paragraphs without
paragraph-level <w:bidi/>. Tests verify that clicking Align Left or
Align Right on these paragraphs stores the display value unchanged
(no mirror), since the paragraph itself is LTR per spec.

…n, and indent

Expands SD-3094 behavior coverage across additional surfaces that share
the alignment-writer code path:

- Headings (Heading1/Heading2 with w:bidi): Align Left/Right mirrors
  the stored OOXML the same way it does for body paragraphs.
- Table cells with RTL direction (w:bidiVisual): Align Left on a
  Hebrew cell paragraph stores w:jc=right.
- Multi-paragraph selection across three RTL paragraphs: Align Left
  applies the writer mirror per-paragraph, all three end up stored
  as w:jc=right.
- Indent + RTL: Increase Indent on an RTL paragraph updates the
  paragraph properties (smoke test against the toolbar indent button).

Lists + RTL alignment was investigated but deferred: it needs a
hand-crafted OOXML fixture with explicit numbering + paragraph-level
bidi, which is a bigger scope and better tracked separately.