False Positive: Roman Numeral 'I' at the End of a Sentence (`SpellCheck`)

**What got flagged?**
`I.`

**Why is this incorrect?**
A roman numeral 1 at the end of a sentence should be recognized as a word just as much as one in the middle of a sentence.

**Example of correct usage:**
```md
The political climate reached a peak following World War I.
```

Start by reproducing the SpellCheck false positive with `I.` and the World War I example, then inspect the spelling or grammar rule that handles Roman numerals at sentence boundaries. Done means a Roman numeral `I` at the end of a sentence is not flagged while the existing behavior for other contexts remains correct.

Written by the indexing model from the issue text.