fix(MD013): preserve wildcard asterisks during reflow

[mattiasgronlund]

Description

Fixes MD013 semantic reflow so the emphasis sentence-split path does not insert a space after a hyphen before a literal wildcard asterisk. This preserves identifiers like TICKET-* during reflow.

The regression test and bug fix were created in cooperation with Codex.

Fixes: #597

Type of Change

• Bug fix (non-breaking change fixing an issue)
• New feature (non-breaking change adding functionality)
• Breaking change (fix or feature causing existing functionality to change)
• Documentation update

Testing

• Tests added/updated
• All tests passing (make test-dev)
• Manual testing performed

Added regression test:

• test_reflow_preserves_literal_wildcard_asterisks

Validated locally:

make test-dev
make fmt
make lint

Checklist

• Code follows project style (make fmt && make lint)
• Conventional commit messages used
• Documentation updated (if needed)
• CHANGELOG.md updated (if user-facing)

[rvben]

Thanks for the fix — the wildcard case is real and reproduces on main.

One concern before merging: the change patches two of three sibling sites in src/utils/text_reflow.rs. The same pattern at line 1477 (the general element-joining path) doesn't get the new !current_line.ends_with('-') check, so a hyphen-attached emphasis going through that path will reintroduce the bug.

Could you either:

• (a) Apply the same && !current_line.ends_with('-') at line 1477, or

• (b) Extract a shared helper, e.g.:

  fn should_insert_space_before_join(current: &str) -> bool {
      !current.is_empty()
          && !current.ends_with(' ')
          && !current.ends_with('(')
          && !current.ends_with('[')
          && !current.ends_with('-')
  }

  and call it at all three sites?

I tested dash-*emphasis* (no space) on this branch and it now produces the correct output, so the fix itself is sound — just want to keep the three sibling conditionals consistent.

Also worth noting: the fix actually addresses a broader class than wildcards specifically — any hyphen-attached emphasis-like construct. The PR title and test could mention that, but not a blocker.

[mattiasgronlund]

I fixed the code according to your comment, using fn should_insert_space_before_join(current: &str) -> bool.

I tried to create a test case which would fail unless I added the fix on line 1477 also, but I had to give up.
I am quite sure that if is_adjacent is false, current_line can not end with '-'.