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_layout.cpp

@@ -49,6 +49,8 @@ int modeCount() {
 // buttons tile into the band MINUS the menu reserve (topToolbarActionRect), so they never run
 // under the menu button (L5 refinement 1).
 
+namespace {
+
 ActionBarRect topToolbarRect(int w) {
     ActionBarRect s;
     s.x = 0;
@@ -67,6 +69,8 @@ MenuBarRect topMenuBarRect(int w) {
 // The More button's rect (right-anchored in the top band). Empty when the band is too narrow
 // to place it clear of its left inset — the three variants stay reachable via their bindable
 // commands (graceful suppression).
+}  // namespace
+
 MenuButtonRect topMenuButtonRect(int w) {
     return computeMenuButton(topMenuBarRect(w), kMenuBtnSpec);
 }
@@ -200,6 +204,8 @@ std::vector<ActionBarRow> overflowMenuRows() {
     };
 }
 
+namespace {
+
 // The active mode id the opposite-mode gate + footer toggle both read (ONE source of truth for
 // "which mode is active"). Empty when no session (every button then falls to fail-open live).
 std::string activeModeIdOrEmpty() {
@@ -207,6 +213,8 @@ std::string activeModeIdOrEmpty() {
     return g_panel.session->view().activeModeId();
 }
 
+}  // namespace
+
 // The BOTTOM toolbar inventory (L5 refinement 3): FOUR Item/Track x Arrange/Design tag buttons
 // then a set-apart Show Both. The suffixes are the ACTUAL registered command-id strings from
 // actions.cpp (VIEW_MOVE_ITEMS_ARRANGE / VIEW_MOVE_ITEMS_DESIGN for the item moves;
@@ -290,6 +298,8 @@ int resolveBarCommandId(const ActionBarRow& row) {
     return NamedCommandLookup(named.c_str());
 }
 
+namespace {
+
 // The current key binding string for a command in the MAIN section, or "" (unbound / not
 // registered). Queried via kbd_getTextFromCmd (SectionFromUniqueID(0)).
 std::string barBindingText(int cmd) {
@@ -300,6 +310,8 @@ std::string barBindingText(int cmd) {
     return {};
 }
 
+}  // namespace
+
 // The flat action index under (x, y) in `bar` for the given row set, or -1 (miss). Pure hit-test.
 int toolbarHit(int x, int y, const ActionBarRect& bar, const std::vector<ActionBarRow>& rows) {
     if (bar.height <= 0) return -1;