Fix e.g./i.e. punctuation rule to eliminate false positives on real words

[Copilot]

The old \b(?:eg|ie)[^,] pattern was matching legitimate words like "egg", "egress", and "ingredient". The rule has been rewritten using proper word boundaries and negative lookahead.

New Punctuation.yml

extends: substitution
message: "Use '%s' instead of '%s'"
level: warning
nonword: true
swap:
  'e\.g\.(?!,)': 'eg,'
  'i\.e\.(?!,)': 'ie,'
  '\beg\b(?!,)': 'eg,'
  '\bie\b(?!,)': 'ie,'

• \beg\b / \bie\b — word boundaries prevent matching inside "egg", "egress", etc.
• nonword: true — required for Vale to tokenize and match period-containing forms like "e.g." and "i.e."
• (?!,) — skips already-correct usage ("eg,", "e.g.,")
• Covers both period-form (e.g., i.e.) and bare abbreviation (eg, ie), enforcing a trailing comma in both cases

Test fixture update

features/rules.feature updated to match current actual Vale output — removes the false-positive "egg" alert lines and corrects the message format from 'eg, or ie,' to 'eg,'.

Original prompt

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This section details on the original issue you should resolve

<issue_title>Come up with a better e.g., i.e. rule</issue_title>
<issue_description>#24</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes Come up with a better e.g., i.e. rule #25

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