fix(subtitles): merge wrapped positioned caption rows (#234)

changes/caption-row-sentence-join.md

@@ -0,0 +1,4 @@
+type: fixed
+area: overlay
+
+- Broadcast-style Japanese caption tracks (Crunchyroll JA subs) that split one sentence across two positioned events now publish it as a single line, so `preserveLineBreaks: false` flattens it, the sidebar lists it once, and mined sentences are whole. Rows from two different speakers, sound effects, and labeled turns still stay on separate lines.