Exempt ReaSampler 9000's own editor from the plugin OS drag hand-off

A dragged bank card over our own instrument's editor was OLE-dropping like a third-party plugin. Classify our channel's own .vst3 module as Instrument, not Plugin, so it keeps the normal instrument-drop outcome.

src/core/ui/window_origin.h

@@ -10,10 +10,11 @@
 namespace reasampler::ui {
 
 enum class WindowCode {
-    Host,     // the host executable itself — REAPER's own chrome and containers
-    System,   // an OS module (standard controls, dialog class): says nothing about who placed it
-    Plugin,   // any other code — a plugin binary, or a window of another process (bridged plugin)
-    Unknown,  // the procedure resolved to no loaded module — no evidence either way
+    Host,        // the host executable itself — REAPER's own chrome and containers
+    System,      // an OS module (standard controls, dialog class): says nothing about who placed it
+    Plugin,      // any other code — a plugin binary, or a window of another process (bridged plugin)
+    Instrument,  // our own ReaSampler 9000 module: FX chrome, not a hand-off-worthy plugin editor
+    Unknown,     // the procedure resolved to no loaded module — no evidence either way
 };
 
 // What the shell observed about ONE window. The CLASS procedure, not the instance one, because an
@@ -23,6 +24,11 @@ struct WindowFacts {
     bool otherProcess = false;  // the window belongs to a process other than the host's
     bool procResolved = false;  // the class procedure lies inside a loaded module
     bool hostModule = false;    // ...and that module is the host executable
+    // ...and that module is THIS channel's ReaSampler 9000 .vst3 (basename match, set by the
+    // shell against app_version::vstOutputName() + ".vst3" — stable and beta each recognise only
+    // their own binary, never the other channel's). A drag over our own instrument's editor is
+    // the load-bearing-principle instrument-drop outcome, not the OS hand-off other plugins get.
+    bool ownModule = false;
     std::string modulePath;     // that module's file path, UTF-8
 };