fix NoPayStation PSP parsing + detail-panel UnboundLocalError

- PSP_GAMES.tsv and PSX_GAMES.tsv use different headers (PSP adds Type/RAP
  columns, PSX adds Original Name). Parse the header row and map columns by
  name instead of hardcoding positions — PSP names were showing as 'Minis'/
  'PC Engine' (the Type column) with broken download URLs.
- GameDetailsPanel.set_item referenced is_ps1 before it was assigned, raising
  UnboundLocalError and leaving the detail panel stale.

app/gui.py

@@ -682,13 +682,13 @@ class GameDetailsPanel(QWidget):
         self.system = item.get("system")
         self._ps1_kind = item.get("ps1_kind")
         path = item.get("path") or ""
+        is_ps1 = item.get("system") == "ps1"
         if (is_ps1 and item.get("ps1_kind") == "eboot") or item.get("psp_kind") == "eboot":
             self.filename.setText(Path(path).parent.name if path else "")
         else:
             self.filename.setText(Path(path).name if path else "")
         self.filename.setToolTip(path)
         self.filename.setVisible(bool(path))
-        is_ps1 = item.get("system") == "ps1"
         is_ps1_disc = is_ps1 and item.get("ps1_kind") == "disc"
         self.play_btn.setEnabled(
             (item.get("system") == "games" and bool(path) and Path(path).suffix.lower() == ".iso")