Name NLB uploads izpisek_YYYY-MM-DD

Back to the dashed date rename_izpiski.py used, so a statement the script
already named is recognised as already there when it is uploaded again,
rather than landing as a second copy under the underscored name.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

CLAUDE.md

@@ -314,7 +314,7 @@ IBAN wrapped across continuation lines stays contiguous for a glob to match.
 A new parser must do the same rather than reintroduce a structured field.
 
 **A parser may name its statements, and only uploads use it.** `parser.Namer` is
-optional, like `parser.Warner`: `nlb` names an izpisek `izpisek_YYYY_MM_DD`
+optional, like `parser.Warner`: `nlb` names an izpisek `izpisek_YYYY-MM-DD`
 after its *Datum izpiska*, ported from the `rename_izpiski.py` it replaced, and
 `traderepublic` names a statement `traderepublic_YYYY_MM_DD_YYYY_MM_DD` after
 the period in its header. A name is derived from what the statement says, never