Fix SWELL drag guard, channel-fork the VST editor window class, dedupe own-module match

Panel drag no longer misfires on SWELL's always-zero wParam; stable/beta VST editors register distinct window classes against their own module instead of colliding on REAPER's; own-module basename matching moves to a tested pure helper.

src/shell/actions/drag_out_win.cpp

@@ -326,25 +326,9 @@ std::string moduleFileName(HMODULE mod) {
     }
 }
 
-// True iff `path`'s file name (the part after the last separator) case-insensitively matches
-// `fileName` — Windows paths are case-insensitive, and GetModuleFileName's casing tracks however
-// the module was loaded (often not the on-disk casing).
-bool sameBaseName(const std::string& path, const std::string& fileName) {
-    const std::size_t pos = path.find_last_of("\\/");
-    const std::string base = pos == std::string::npos ? path : path.substr(pos + 1);
-    if (base.size() != fileName.size()) return false;
-    for (std::size_t i = 0; i < base.size(); ++i) {
-        char a = base[i], b = fileName[i];
-        if (a >= 'A' && a <= 'Z') a = static_cast<char>(a - 'A' + 'a');
-        if (b >= 'A' && b <= 'Z') b = static_cast<char>(b - 'A' + 'a');
-        if (a != b) return false;
-    }
-    return true;
-}
-
 // This channel's own ReaSampler 9000 module file name (e.g. "reasampler_9000.vst3", or the
-// "_beta" variant) — the same name CMake gives the built .vst3 (OUTPUT_NAME + SUFFIX), so stable
-// and beta each recognise only their own binary, never the other channel's.
+// "_beta" variant) — the same name CMake gives the built .vst3 (OUTPUT_NAME + SUFFIX). Matching
+// logic lives in core/ui/window_origin's isOwnModulePath; see there.
 const std::string& ownVstFileName() {
     static const std::string name = version::vstOutputName() + ".vst3";
     return name;
@@ -385,7 +369,7 @@ ui::WindowFacts windowFacts(HWND hwnd) {
     // (string-building) lookup in that case.
     if (!f.hostModule) {
         f.modulePath = moduleFileName(mod);
-        f.ownModule = sameBaseName(f.modulePath, ownVstFileName());
+        f.ownModule = ui::isOwnModulePath(f.modulePath, ownVstFileName());
     }
     return f;
 }

src/shell/actions/drag_out_win.h

@@ -68,9 +68,13 @@ bool pointerOverHostWindow(int screenX, int screenY);
 //   - an all-#32770 dialog-based editor (the generic Windows dialog class) resolves to no
 //     recognizable plugin module — falls to REAPER's outcome;
 //   - a .NET/WPF editor's class procedure is a CLR-thunked address with no resolvable module —
-//     also falls to REAPER's outcome;
+//     also falls to REAPER's outcome; `[verify]`;
 //   - our own ReaSampler 9000 module (this channel's reasampler_9000[_beta].vst3, matched by
-//     basename) also falls to REAPER's outcome, deliberately — see ui::WindowFacts::ownModule.
+//     basename) also falls to REAPER's outcome, deliberately — see ui::WindowFacts::ownModule;
+//   - ReaSampler 9000 itself run bridged/in a separate process reads as Plugin, same as any other
+//     bridged plugin — banner (the OS hand-off fires over our own editor), harmless;
+//   - a renamed ReaSampler 9000 binary (the basename no longer matches ownVstFileName()) misses
+//     the exemption and reads as Plugin — banner, harmless.
 // The opposite direction is unguarded: a third-party hook that replaces REAPER's own chrome
 // class procedure via SetClassLongPtr(GCLP_WNDPROC) would make REAPER's own window read as
 // Plugin — toward OLE instead of away from it.