fix(docx): keep non-breaking hyphens

[breken-ai]

What

The DOCX run walker now turns w:noBreakHyphen into a -. It keeps the run's style.

Why

Word stores a non-breaking hyphen (Ctrl+Shift+-) as its own run element, not as a character inside w:t. The walker's match had no arm for it, so the hyphen disappeared and the text on either side ran together:

<w:r><w:t>Call 555</w:t><w:noBreakHyphen/><w:t>0123 by e</w:t><w:noBreakHyphen/><w:t>mail</w:t></w:r>

• before: Call 5550123 by email
• after: Call 555-0123 by e-mail

The other readers already handle this character. The .doc reader maps 0x1E to - and the RTF reader maps \_ to -. So one document saved as .doc or .rtf kept its phone numbers, part numbers and hyphenated words, but saved as .docx it lost them.

Testing

• New test non_breaking_hyphen_renders_as_a_hyphen in src/formats/docx/mod.rs. It fails on main (left: "Call 5550123 by email\n") and passes with the fix.
• cargo test --locked: 287 unit, 1 robustness and 9 snapshot tests pass, 1 ignored, as on main.
• cargo fmt --all --check and cargo clippy -p anydoc --all-targets --all-features -- -D warnings are clean.

This PR was prepared with AI assistance (Claude Code) and reviewed before submission.

🤖 Generated with Claude Code

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Summary by cubic

Fixes the DOCX run walker so non-breaking hyphens render as - instead of vanishing, which previously joined text on either side ("5550123" instead of "555-0123").

• Emits a - with the run's style, matching how the .doc and RTF readers already handle the same character.
• Adds a regression test that fails on main and passes with this change.

^{Written for commit 21eecd9. Summary will update on new commits.}

[cubic-dev-ai]

No issues found across 2 files

Confidence score: 5/5

• Automated review surfaced no issues in the provided summaries.
• No files require special attention.

_{Re-trigger cubic}