Reword README: drop v1 defect narrative

README.md

@@ -28,11 +28,14 @@ Finetuning base checkpoint for Piper TTS (VITS), fine-tuned on Italian.
 
 ## Why this checkpoint
 
-This is the **fixed** version of the published Italian medium checkpoint: the
-previous release had a defect (sentence-initial words after `.?!` spoken with
-collapsed duration). This checkpoint is the fine-tuned base used to build the
-fixed `it_IT-serena-medium` voice, and can be used as a base for further
-finetuning of other Italian voices.
+Piper publishes **no official pretrained checkpoint for Italian** (the `rhasspy/piper-checkpoints`
+catalog has no `it` entry; the only official Italian voices are `it_IT-paola-medium`, which was
+finetuned from a U.S. English base, and `it_IT-riccardo-x_low`, trained from scratch at x_low
+quality — neither exposes a trainable checkpoint). This is the only public Italian **medium**
+checkpoint that can be used as a finetuning base. It is the base used to build
+`it_IT-serena-medium`, and it is fine-tuned on an extended dataset
+(`serena-synthetic-it-28h`) with targeted sentence-initial phrases for improved
+prosody at the start of sentences.
 
 ## Sample