Fix crash: Update header — Timer-based scan, no background thread

Source/PluginBridgeProcessor.h

@@ -5,7 +5,8 @@
 #include "McpServer.h"
 #include "HostedPluginManager.h"
 
-class PluginBridgeProcessor : public juce::AudioProcessor
+class PluginBridgeProcessor : public juce::AudioProcessor,
+                               private juce::Timer
 {
 public:
     PluginBridgeProcessor();
@@ -45,21 +46,33 @@ public:
     // Load plugin (called on message thread)
     void loadPluginFromFile(const juce::File& file);
 
-    // Plugin scanning (owned by Processor — safe lifetime)
+    // Plugin scanning — runs on message thread via Timer (safe for NSAlert-showing plugins)
     void startPluginScan();
-    bool isScanComplete() const { return scanComplete; }
-    bool isScanning() const { return scanning; }
+    bool isScanComplete() const { return scanComplete.load(); }
+    bool isScanning() const { return scanning.load(); }
     const juce::Array<juce::PluginDescription>& getScannedPlugins() const { return scannedPlugins; }
 
 private:
+    void timerCallback() override;
+
     HostedPluginManager hostManager;
     McpServer mcpServer;
     static constexpr int kDefaultMcpPort = 16620;
 
-    // Plugin scan state (lives in Processor — safe)
+    // Plugin scan state
     juce::Array<juce::PluginDescription> scannedPlugins;
     std::atomic<bool> scanComplete{false};
     std::atomic<bool> scanning{false};
 
+    // Scanner internals (only alive during scan)
+    struct ScannerState {
+        std::unique_ptr<juce::PluginDirectoryScanner> scanner;
+        bool done = false;
+    };
+    juce::OwnedArray<ScannerState> scanners;
+    int currentScannerIndex = 0;
+    std::unique_ptr<juce::AudioPluginFormatManager> scanFormatManager;
+    std::unique_ptr<juce::KnownPluginList> scanList;
+
     JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR(PluginBridgeProcessor)
 };