Report CLI save failures and validate advert intervals

Roll back failed password and advert changes, propagate identity-store results, and report unsaved common and observer settings. Correct observer filter persistence and KISS OTA capability claims. Add fault-injection and packaging regressions.

examples/simple_sensor/SensorMesh.cpp

@@ -1092,7 +1092,7 @@ bool SensorMesh::formatFileSystem() {
 #endif
 }
 
-void SensorMesh::saveIdentity(const mesh::LocalIdentity& new_id) {
+bool SensorMesh::saveIdentity(const mesh::LocalIdentity& new_id) {
 #if defined(NRF52_PLATFORM) || defined(STM32_PLATFORM)
   IdentityStore store(*_fs, "");
 #elif defined(ESP32)
@@ -1102,7 +1102,7 @@ void SensorMesh::saveIdentity(const mesh::LocalIdentity& new_id) {
 #else
   #error "need to define saveIdentity()"
 #endif
-  store.save("_main", new_id);
+  return store.saveWithRetry("_main", new_id);
 }
 
 void SensorMesh::applyTempRadioParams(float freq, float bw, uint8_t sf, uint8_t cr, int timeout_mins, uint16_t preamble) {