S4 Tier 0: the bank plays — VST3 marshals MIDI to the S3 core, reads the live bank + resolves WAV the M4 way, mono downmix, lock-free load handoff, LICE sample-pick

src/capture_paths.cpp

@@ -5,6 +5,7 @@
 #include <cstdint>
 #include <cstdio>
 #include <cstring>  // std::memcmp
+#include <filesystem>
 #include <vector>
 
 namespace reasampler {
@@ -213,6 +214,15 @@ std::string resolveBankFile(const std::string& projectDir,
     return dir + "/" + rel;
 }
 
+std::string projectDirOfRpp(const std::string& rppPath) {
+    // An unsaved project reports an empty .rpp path; keep it empty so downstream
+    // resolution refuses (no default-location fallback). Mirrors persist.cpp's prior
+    // projectDirOf exactly: parent_path of the .rpp, then normalizeSlashes.
+    if (rppPath.empty()) return {};
+    std::string dir = std::filesystem::path(rppPath).parent_path().string();
+    return normalizeSlashes(dir);
+}
+
 BankRelocation deriveRelocationPlan(const std::string& oldProjectDir,
                                     const std::string& newProjectDir) {
     BankRelocation r;