fix: honor docDefaults direction cascade and preserve run-level w:rtl on export

[artem-harbour]

Additional RTL gaps.

• Added docDefaults paragraph direction fallback in pm-adapter direction resolution (paragraph -> section -> docDefaults -> run inference -> LTR).
• Fixed run-level RTL export preservation: runProperties.rtl is now retained in w:rPr export path even with inline/style key filtering.
• Added coverage:
  • docDefaults precedence tests in paragraph direction logic.
  • w:rtl decode/export tests (rtl/rPr/r translators).
  • Footer roundtrip regression test proving <w:rtl/> survives import/export.
• Result: closes two high-priority RTL gaps (template docDefaults direction and footer run-level RTL loss).

[github-actions]

The ecma-spec MCP tools aren't permitted yet. Could you approve the mcp__ecma-spec__ooxml_element (and related) tool calls? They're needed to look up the w:rtl and w:rPr element definitions against the ECMA-376 spec.

Once you grant permission, I can check:

1. Whether w:rtl is a valid child of w:rPr
2. What attributes w:rtl accepts (specifically whether w:val='0' is a valid suppression form)
3. Whether the { attributes: {} } form (omitting w:val) is the correct way to express "RTL enabled"

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.

📢 Thoughts on this report? Let us know!