import: a .rsbank lands as a new bank, whole or not at all

Four collisions answered explicitly: ids reminted, names never overwritten,
content deduped before the write, bank name auto-suffixed. Degraded ledger
refuses before the picker.

src/app/main.cpp

@@ -36,6 +36,7 @@
 #include "shell/panel/panel_window.h"            // panel lifecycle (init/toggle/open-query/shutdown)
 #include "shell/persist/session.h"               // ReaSamplerSession
 #include "shell/view/view.h"                     // reconcileManagedLanes / applyMode
+#include "shell/actions/package_import_action.h" // bank-package import action body
 
 namespace capture = reasampler::capture;
 
@@ -91,6 +92,7 @@ static void RunCancelRealtime(int)    { capture::RunCancelRealtime(g_session); }
 static void RunRecaptureFromSource(int) { capture::RunRecaptureFromSource(g_session); }
 static void RunRenderTrackInPlace(int) { capture::RunRenderTrackInPlace(g_session); }
 static void RunResampleBake(int)      { capture::RunResampleBake(g_session); }
+static void RunImportBankPackage(int) { reasampler::doImportBankPackage(g_session); }
 static void RunShowVersion(int) {
     // On-demand only — no unconditional startup print (routine console chatter pops
     // the console window).
@@ -148,6 +150,8 @@ static std::vector<reasampler::ActionTableRow> buildMainActionTable() {
                     "land pending ReaSampler 9000 resample bake",
                     &RunResampleBake});
     rows.push_back({"SHOW_VERSION", "show version", &RunShowVersion});
+    rows.push_back({"IMPORT_BANK_PACKAGE", "import bank package (.rsbank)",
+                    &RunImportBankPackage});
 
     return rows;
 }