Fix crash: Add validatePluginFile and lastError to header

Source/HostedPluginManager.h

@@ -15,6 +15,7 @@ public:
     void unloadPlugin();
     bool isLoaded() const;
     juce::String getPluginName() const;
+    juce::String getLastError() const { return lastError; }
 
     // Audio processing — called from audio thread
     void prepareToPlay(double sampleRate, int blockSize);
@@ -26,7 +27,7 @@ public:
         int index;
         juce::String id;
         juce::String name;
-        float value;        // 0.0–1.0 normalized
+        float value;
         juce::String displayText;
         bool automatable;
     };
@@ -39,10 +40,12 @@ public:
     // Thread safety
     juce::CriticalSection& getPluginLock() { return pluginLock; }
 
-    // File path of currently loaded plugin (for state save/restore)
+    // File path of currently loaded plugin
     juce::String getLoadedPluginPath() const;
 
 private:
+    bool validatePluginFile(const juce::File& pluginFile);
+
     juce::AudioPluginFormatManager formatManager;
     std::unique_ptr<juce::AudioPluginInstance> hostedPlugin;
     juce::CriticalSection pluginLock;
@@ -50,6 +53,7 @@ private:
     double currentSampleRate = 44100.0;
     int currentBlockSize = 512;
     juce::String loadedPluginPath;
+    juce::String lastError;
 
     JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR(HostedPluginManager)
 };