Suppress cppcheck warnings for CI compatibility

Add missingInclude suppression to prevent false positives on fresh CI checkouts where include paths are unresolved. Add inline suppression for constVariableReference warning where cppcheck cannot detect mutations without full include path resolution.

platformio.ini

@@ -13,7 +13,10 @@ framework = arduino
 monitor_speed = 115200
 upload_speed = 921600
 check_tool = cppcheck
-check_flags = --enable=all --suppress=missingIncludeSystem --suppress=unusedFunction --suppress=unmatchedSuppression --suppress=*:*/.pio/* --inline-suppr
+; missingInclude (project headers) is suppressed alongside missingIncludeSystem: on a
+; fresh CI checkout cppcheck has no resolved include paths, so it reports every
+; project header as missing (~470 information-level lines) and fails the job.
+check_flags = --enable=all --suppress=missingIncludeSystem --suppress=missingInclude --suppress=unusedFunction --suppress=unmatchedSuppression --suppress=*:*/.pio/* --inline-suppr
 check_skip_packages = yes
 
 board_upload.flash_size = 16MB

src/activities/settings/BleButtonMapActivity.cpp

@@ -46,6 +46,9 @@ void BleButtonMapActivity::onExit() {
 
 bool BleButtonMapActivity::assignCapturedKey(MappedInputManager::Button button) {
   const uint8_t btn = static_cast<uint8_t>(button);
+  // Mutated via std::replace_if below and through `slot`; cppcheck's CI parse
+  // (no include paths) can't see the writes and suggests const.
+  // cppcheck-suppress constVariableReference
   auto& map = SETTINGS.bleKeyMap;
   using Entry = CrossPointSettings::BleKeyMapEntry;
   const uint8_t kind = capturedKind;