chore(bank_panel): clean up persistBook dead code and stale comment; align transfer switch to explicit enum cases

src/bank_panel.cpp

@@ -1180,14 +1180,11 @@ bool regionAt(int x, int y, Region& out) {
 
 // --- Bank management ops (id-keyed; drive the B1 model + persist) --------------
 //
-// Each op mutates g_session.book() then persists via saveToActiveProject(). After a
+// Each op mutates g_session.book() then persists via persistBankOp(). After a
 // STRUCTURAL mutation (create/delete/evacuate) any Bank*/BankIndex& is invalid — we
-// resolve fresh, pass ids, and let the next refreshFingerprint repaint. persistBook
-// no-ops on an unsaved project (matches the capture/B3 quiet-persist idiom).
-
-void persistBook() {
-    if (g_panel.session) g_panel.session->saveToActiveProject();
-}
+// resolve fresh, pass ids, and let the next refreshFingerprint repaint. On an
+// unsaved project the empty-close discard in persistBankOp ensures no stale state
+// survives (matches the capture/B3 quiet-persist idiom).
 
 // REAPER's stock single-line input (comma-safe via the \x1f return separator, as B3).
 bool promptText(const char* title, const char* caption, const std::string& initial,
@@ -1319,9 +1316,11 @@ void transferSamples(const std::vector<std::string>& sampleIds,
                  : book()->moveSample(sid, srcBankId, destBankId);
         switch (r) {
             case TransferResult::Moved:
-            case TransferResult::Copied:    ++ok; break;
-            case TransferResult::Collapsed: ++collapsed; break;
-            default: break;
+            case TransferResult::Copied:        ++ok; break;
+            case TransferResult::Collapsed:     ++collapsed; break;
+            case TransferResult::RejectedUnknownBank:
+            case TransferResult::RejectedSampleAbsent:
+            case TransferResult::RejectedSameBank: break;
         }
     }
     const bool mutated = copy ? (ok > 0) : (ok > 0 || collapsed > 0);