Fixed line breaking that would split words like "équivaut" into "é" on one
line and "quivaut" on the next line, even though they're part of the same word.
Root cause analysis (from debug logging):
When text contains accented characters in decomposed form (e + combining
accent), the system processes them as separate atoms:
1. "é" is processed as an accent atom, composed, and added to currentLine
2. "quivaut " is processed as the next ordinary atom
3. Before adding "quivaut ", checkAndPerformInteratomLineBreak() is called
4. This function sees that adding "quivaut " would exceed maxWidth
5. It breaks and flushes the line with "é" at the end
6. "quivaut " starts on a new line
Result: "é" appears alone at the end of one line, "quivaut " on the next.
The fix:
Modified checkAndPerformInteratomLineBreak() in MTTypesetter.swift to detect
when we're about to break in the middle of a word.
