Q-W2 review follow-ups: anon-namespace TU-private panel helpers, fix stale bank_panel.cpp comments, correct shim-transitivity claim

Wraps ~50 file-local helpers across all eight panel TUs in namespace{} (dissolves the menuAppend default-arg ODR trap); zero behavior change, 60/60 green.

src/shell/panel/panel_bank_ops.cpp

@@ -87,6 +87,8 @@ std::vector<const Bank*> namedBanks() {
 // unsaved project the empty-close discard in persistBankOp ensures no stale state
 // survives (matches the capture/B3 quiet-persist idiom).
 
+namespace {
+
 // 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,
                 std::string& out) {
@@ -111,6 +113,8 @@ std::string mintBankId() {
     return std::string(buf);
 }
 
+}  // namespace
+
 void doCreateBank() {
     if (!book()) return;
     std::string name;
@@ -127,6 +131,8 @@ void doCreateBank() {
     invalidatePanel();
 }
 
+namespace {
+
 void doRenameBank(const std::string& bankId) {
     if (!book()) return;
     const Bank* bk = book()->bank(bankId);
@@ -198,6 +204,8 @@ void doActivateBank(const std::string& bankId) {
     invalidatePanel();
 }
 
+}  // namespace
+
 // Move or copy `sampleIds` from `srcBankId` to `destBankId` (index-only). Both pass
 // ids straight to the model op (no BankModel& cached across the loop's mutations).
 //
@@ -312,6 +320,8 @@ std::vector<std::string> resolveDragPathsForOs() {
 // Menu command ids are LOCAL to the popup (not REAPER action ids) — TPM_RETURNCMD
 // hands the chosen id straight back, so no hookcommand routing is involved.
 
+namespace {
+
 // Appends a string item (id) to `menu` at its end. Portable over Win32/SWELL: both
 // accept InsertMenu(menu, pos, MF_BYPOSITION|MF_STRING, id, text) with a negative
 // position appending. Win32 and SWELL both treat pos < 0 as an append.
@@ -337,6 +347,8 @@ enum : unsigned int {
     kMenuCopyBase = 2000,   // copy-to-bank: kMenuCopyBase + destination index
 };
 
+}  // namespace
+
 // Shows the right-click context menu for a named-bank TAB: activate / rename / delete
 // / evacuate that bank, plus a create entry. Drives the id-keyed ops.
 void showTabMenu(int screenX, int screenY, const std::string& bankId) {