feat(persist): persist BankBook under banks key, retire legacy bank_index, route capture to active bank (B2)

src/main.cpp

@@ -111,9 +111,10 @@ static int g_cmdCancelRealtime = 0;
 
 // The persistence session (M4): owns the in-memory BankIndex and bridges it to
 // project ext state. A timer tick drives g_session.poll() to detect project
-// load / Save-As; capture adds Samples to g_session.bank(); after a capture we
-// serialize the bank back into the active project's ext state so it travels with
-// the .rpp. Replaces the M3 session-only g_bank.
+// load / Save-As; capture adds Samples to g_session.bank() — which (B2) resolves to
+// the ACTIVE bank's index inside the session's BankBook; after a capture we serialize
+// the book back into the active project's ext state (the `banks` key) so it travels
+// with the .rpp. Replaces the M3 session-only g_bank.
 static reasampler::ReaSamplerSession g_session;
 
 // --- M8 in-flight realtime capture (async, timer-driven) --------------------
@@ -133,8 +134,9 @@ static reasampler::RealtimeCaptureHandle    g_rtCapture;
 static ReaProject* g_rtCaptureProject = nullptr;
 
 // Commit a finished realtime capture (a Done tick/abort with an Ok result): add the
-// Sample to the bank, persist + MarkProjectDirty, log. Shared by the tick-completion
-// path and the abort paths. On a non-Ok result, logs the failure only.
+// Sample to the ACTIVE bank (g_session.bank() resolves to book.activeIndex() — B2),
+// persist + MarkProjectDirty, log. Shared by the tick-completion path and the abort
+// paths. On a non-Ok result, logs the failure only.
 static void CommitRealtimeResult(const reasampler::CaptureResult& res)
 {
     if (res.status != reasampler::CaptureStatus::Ok)
@@ -547,10 +549,12 @@ static void RunCapture(const reasampler::CaptureActionDef& def)
         return;
     }
 
+    // Add to the ACTIVE bank: g_session.bank() resolves to book.activeIndex() (B2).
     reasampler::AddResult added = g_session.bank().add(res.sample);
-    // Persist the updated bank into the active project's ext state so the capture
-    // survives Save / close+reopen (M4) and travels with the .rpp. saveToActiveProject
-    // also calls MarkProjectDirty. Non-destructive: writes only our own ext-state key.
+    // Persist the updated book into the active project's ext state (the `banks` key)
+    // so the capture survives Save / close+reopen (M4) and travels with the .rpp.
+    // saveToActiveProject also clears the retired legacy key and calls MarkProjectDirty.
+    // Non-destructive: writes only our own ext-state keys.
     g_session.saveToActiveProject();
 
     std::string log = "ReaSampler: " + res.message + "\n";