feat: show only the translated subtitle once translation finishes

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

src/mpv/mpvitem.h

@@ -66,9 +66,9 @@ public:
     Q_INVOKABLE void seek(double seconds);
     // Adds an external subtitle file and makes it the primary subtitle.
     Q_INVOKABLE void addSubtitleFile(const QUrl &url);
-    // Shows \a url as the secondary subtitle, adding it first (named \a title) unless it
-    // is already loaded.
-    Q_INVOKABLE void showSecondarySubtitleFile(const QUrl &url, const QString &title);
+    // Makes \a url the only subtitle shown, adding it first (named \a title) unless it is
+    // already loaded.
+    Q_INVOKABLE void showTranslatedSubtitleFile(const QUrl &url, const QString &title);
     // Shows a short message on mpv's on-screen display.
     Q_INVOKABLE void showText(const QString &text);
 
@@ -90,6 +90,7 @@ private:
     void setFileLoaded(bool loaded);
     void updateTracks(const QVariantList &trackList);
     void applyUserConfig();
+    void showOnlySubtitle(int id);
 
     bool m_ready = false;
     QUrl m_pendingUrl;
@@ -103,8 +104,8 @@ private:
     int m_subtitleId = 0;
     int m_secondarySubtitleId = 0;
     double m_subtitleDelay = 0.0;
-    // File added by showSecondarySubtitleFile() that should become secondary once mpv lists it.
-    QString m_pendingSecondaryPath;
+    // File added by showTranslatedSubtitleFile() that should be shown once mpv lists it.
+    QString m_pendingTranslatedPath;
     bool m_loadUserConfig = false;
     QStringList m_loadedUserConfigFiles;
     QStringList m_skippedUserOptions;