TTS reads raw text digit-by-digit with no number/date normalization layer.
Short numbers like 1414 were read as a single 4-digit number (tysyacha
chetyresta chetyrnadtsat) instead of a spoken code, and dates like '25
chisla' were read in the wrong grammatical case (dvadtsat pyat chislo
instead of dvadtsat pyatogo chisla). Extend the voice delivery_hint with
explicit spell-out rules so the model itself produces already-correct
spoken-form text.