fix(go/fio): nested-table early exit + non-padded date parsing

extractSecondTableRows tracked a boolean inTarget flag and exited on
the first </table> token while inside the target. Any nested <table>
(e.g. pagination markup in the real Fio page) would cause an early
return before reading any data rows, explaining the 0-transaction report.
Fixed by tracking targetDepth instead: depth increments on every <table>
inside the target and we only return when it reaches 0 again.

parseCzechDate also only tried zero-padded layouts ("02.01.2006").
The real Fio transparent page emits non-padded dates ("7.5.2026");
added "2.1.2006" and "2/1/2006" as the preferred layouts.

Also adds a dry-run diagnostic line ("fetched N transaction(s) from Fio")
so the fetch vs dedup split is visible without reading logs.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

go/internal/services/banksync/sync.go

@@ -87,6 +87,10 @@ func SyncToSheets(
 	if err != nil {
 		return 0, fmt.Errorf("sync: fetch fio: %w", err)
 	}
+	if opts.DryRun {
+		fmt.Printf("Dry run: window %s to %s, fetched %d transaction(s) from Fio\n",
+			from.Format("2006-01-02"), to.Format("2006-01-02"), len(txns))
+	}
 
 	// 4. Append new rows.
 	var newRows [][]any