Re.Pcre.split drops leading empty fields, causing playlist entries
such as "#EXTINF:,- songname" to retain the leading dash.
Handle the leading separator explicitly to preserve the expected song metadata.
--- ../src/core/builtins/playlist_basic.ml	2026-10-10 18:05:28.460055350 +0300
+++ ../src/core/builtins/playlist_basic.ml	2026-10-10 18:06:11.580004976 +0300
@@ -61,7 +61,12 @@
         | "" -> meta
         | duration -> ("extinf_duration", duration) :: meta
     in
-    let lines = Re.Pcre.split ~rex:(Re.Pcre.regexp "\\s*-\\s*") song in
+    let lines =
+      let song = String.trim song in
+      if String.length song > 0 && song.[0] = '-' then
+        [""; String.sub song 1 (String.length song - 1)]
+      else Re.Pcre.split ~rex:(Re.Pcre.regexp "\\s*-\\s*") song
+    in
     meta
     @
       match lines with