capture: render a ranged item capture time-bounded — the selected-items source can't narrow a window, only a full-extent one uses it

sourceModeForScope now takes the item extent vs. the requested window. Full-extent item captures and the batch keep the old path unchanged.

src/shell/capture/capture_orchestrator.cpp

@@ -16,6 +16,7 @@
 #include "shell/persist/session.h"             // ReaSamplerSession
 #include "shell/capture/insert.h"              // runInsert / InsertRequest
 #include "shell/capture/realtime_lifecycle.h"  // the in-flight realtime state
+#include "shell/capture/render_selection.h"    // RenderTrackSelection
 
 #include "reaper_plugin.h"  // UNDO_STATE_MISCCFG
 
@@ -181,6 +182,14 @@ CaptureResult renderOffline(CaptureScope scope,
                             const CaptureRequest& req)
 {
     ReaProject* proj = EnumProjects(-1, nullptr, 0);
+    // A selected-tracks render prints the DAW's track selection, so the request's
+    // own tracks must BE that selection for the render — the plain track scope
+    // already resolved them from the live selection (identity), but a ranged item
+    // capture and a re-capture-from-source both name tracks the user has not
+    // selected. Both guards outlive the render call and restore on every path.
+    std::optional<RenderTrackSelection> selection;
+    if (req.sourceMode == SourceMode::SelectedTracks)
+        selection.emplace(sourceTracks);
     FxBypassGuard fxGuard(scope, sourceTracks, proj);
     OfflineRenderBackend backend;
     return backend.capture(req);
@@ -217,7 +226,7 @@ CaptureResult captureAndIndexOne(ReaSamplerSession& session,
     const TailSetting tail = bankPanelTailSetting();
 
     CaptureRequest req;
-    req.sourceMode   = sourceModeForScope(scope);
+    req.sourceMode   = sourceModeForScope(scope, src.itemExtentIsWindow);
     req.startSeconds = startSeconds;        // exact bounds — no rounding
     req.endSeconds   = endSeconds;
     req.wetDry       = 1.0;                 // wet post the FX left enabled by the scope