makeParagraphKey static method
Create a stable key from paragraph text (first 50 chars + length).
Implementation
static String makeParagraphKey(String plainText) {
final clean = plainText.replaceAll('\u00AD', '').trim();
final prefix = clean.length > 50 ? clean.substring(0, 50) : clean;
return '${prefix.hashCode}_${clean.length}';
}