S17 drop-and-load onto track FX button; S13 editor drop-accept (relay degraded)

S17: drag_out InstrumentDrop gesture + instrument_drop blob reusing the
instrument's own serializer; bank_panel FX hover-track + add-VST/vst_chunk
inject. S13 relay deferred (read-only bridge) — editor shows drop affordance.

src/vst/reasampler_editor.cpp

@@ -28,6 +28,7 @@
 
 #ifdef _WIN32
 #include <windowsx.h>  // GET_X_LPARAM / GET_Y_LPARAM
+#include <shellapi.h>  // DragAcceptFiles / DragQueryFile / DragFinish — S13 editor drop-accept
 
 #include "wdltypes.h"
 #include "lice/lice.h"
@@ -218,6 +219,12 @@ void ReaSamplerEditor::onSyncTimer() {
         refreshFromBank();
         invalidate();
     }
+
+    // S13: decay the drop-affordance banner so it auto-dismisses a few ticks after a drop.
+    if (dropHintTicks_ > 0) {
+        --dropHintTicks_;
+        invalidate();
+    }
 }
 #endif  // _WIN32
 
@@ -522,6 +529,10 @@ void ReaSamplerEditor::attachedToParent() {
                                  r.getWidth(), r.getHeight(), parent, nullptr, hInst, nullptr);
     if (childHwnd_) {
         SetWindowLongPtr(childHwnd_, GWLP_USERDATA, reinterpret_cast<LONG_PTR>(this));
+        // S13: accept OS file drops on the editor window (WM_DROPFILES). The drop is NOT
+        // ingested here (the relay is degraded — see onFilesDropped); accepting it lets us show
+        // the "drop on the panel" affordance instead of the OS bouncing the drop silently.
+        DragAcceptFiles(childHwnd_, TRUE);
         // Start the S9/S8 change-detection poll (UI thread). Tied to the child window's
         // lifetime — created here, killed in removedFromParent — so an instance whose editor
         // is closed does NOT poll (the editor-open-only cadence; see the handoff limitation).
@@ -697,6 +708,19 @@ void ReaSamplerEditor::paint(HDC hdc) {
         paintBrowser(&bmp, w, h);
     }
 
+    // S13 (relay degraded): a transient banner flashed after a file was dropped ON THIS window.
+    // It reiterates the shipped ingest gesture rather than swallowing the drop silently. Drawn
+    // LAST so it overlays the mode content; decays via onSyncTimer (dropHintTicks_).
+    if (dropHintTicks_ > 0) {
+        const int bannerH = (std::min)(kTitleHeight + 8, h);
+        Rect banner{0, bands.toggleZones.bottom, w, bands.toggleZones.bottom + bannerH};
+        LICE_FillRect(&bmp, banner.left, banner.top, banner.width(), banner.height(),
+                      kColTabActiveBg, 1.0f, 0);
+        drawTextCentered(&bmp, banner,
+                         "Dropped here isn't loaded yet - drop files onto the ReaSampler bank panel to add them.",
+                         kRgbText);
+    }
+
     BitBlt(hdc, 0, 0, w, h, bmp.getDC(), 0, 0, SRCCOPY);
 }
 
@@ -706,7 +730,16 @@ void ReaSamplerEditor::paintEmptyState(LICE_IBitmap* bmp, const Rect& area) {
     const char* msg = samples_.empty()
         ? "No captures in this project yet - capture audio into the bank to play it here."
         : "No captures in this bank filter. Choose another bank tab above.";
-    drawTextCentered(bmp, area, msg, kRgbDim);
+    // Split the area so the primary line sits centered and the S13 ingest affordance sits just
+    // below it. The affordance is the SHIPPED ingest gesture (drop onto the docked panel) — kept
+    // discoverable here regardless of whether a drop ever lands on THIS window.
+    Rect primary{area.left, area.top, area.right, area.top + area.height() / 2};
+    Rect hint{area.left, primary.bottom, area.right, area.bottom};
+    drawTextCentered(bmp, primary, msg, kRgbDim);
+    drawTextCentered(bmp,
+                     hint,
+                     "To add a sample: drop a file onto the ReaSampler bank panel (the docked window).",
+                     kRgbDim);
 }
 
 void ReaSamplerEditor::paintBrowser(LICE_IBitmap* bmp, int w, int h) {
@@ -1559,6 +1592,20 @@ void ReaSamplerEditor::onSearchChar(unsigned int ch) {
     invalidate();
 }
 
+void ReaSamplerEditor::onFilesDropped(int droppedCount) {
+    // S13 relay DEGRADED. The instrument is a read-only bank consumer and the cross-artifact
+    // ingest relay (editor drop -> extension) is not shipped (see the header note + the handoff
+    // decision point), so we do NOT ingest the dropped files and — load-bearing — NEVER insert a
+    // timeline item. Instead of silently swallowing the drop, flash a clear affordance pointing
+    // at the shipped ingest gesture. dropHintTicks_ counts sync ticks (kSyncTimerIntervalMs
+    // each); ~6 ticks keeps the banner up a few seconds, then onSyncTimer decays it to 0.
+    (void)droppedCount;  // count is informational; the banner text is drop-count-agnostic
+    dropHintTicks_ = 6;
+#ifdef _WIN32
+    invalidate();
+#endif
+}
+
 LRESULT CALLBACK ReaSamplerEditor::wndProc(HWND hwnd, UINT msg, WPARAM wParam,
                                            LPARAM lParam) {
     auto* self =
@@ -1612,6 +1659,16 @@ LRESULT CALLBACK ReaSamplerEditor::wndProc(HWND hwnd, UINT msg, WPARAM wParam,
                 self->invalidate();
             }
             return 0;
+        case WM_DROPFILES: {
+            // S13 (relay degraded): count the dropped files and flash the affordance. We do NOT
+            // read/ingest the paths (the instrument never ingests — the relay to the extension is
+            // unshipped); DragQueryFile with 0xFFFFFFFF just returns the count for the banner.
+            HDROP drop = reinterpret_cast<HDROP>(wParam);
+            const UINT count = DragQueryFileW(drop, 0xFFFFFFFF, nullptr, 0);
+            DragFinish(drop);
+            if (self) self->onFilesDropped(static_cast<int>(count));
+            return 0;
+        }
         case WM_TIMER:
             if (self && wParam == kSyncTimerId) self->onSyncTimer();
             return 0;