Introduce watchdog and serialization improvements

- Added watchdog timer for improved system stability and responsiveness.
- Switched save data serialization to Bincode for better efficiency.
- Enhanced compatibility by supporting fallback to older JSON format.
- Improved logging during flash operations for easier debugging.
- Simplified SavegameManager by managing storage directly.

Software/MainBoard/rust/src/hal/esp.rs

@@ -140,7 +140,8 @@ macro_rules! mk_static {
 
 impl Esp<'_> {
     pub fn get_time(&self) -> DateTime<Utc> {
-        DateTime::from_timestamp_micros(self.rtc.current_time_us() as i64).unwrap_or(DateTime::UNIX_EPOCH)
+        DateTime::from_timestamp_micros(self.rtc.current_time_us() as i64)
+            .unwrap_or(DateTime::UNIX_EPOCH)
     }
 
     pub fn set_time(&mut self, time: DateTime<Utc>) {
@@ -517,10 +518,7 @@ impl Esp<'_> {
         Ok(*stack)
     }
 
-    pub fn deep_sleep(
-        &mut self,
-        duration_in_ms: u64,
-    ) -> ! {
+    pub fn deep_sleep(&mut self, duration_in_ms: u64) -> ! {
         // Mark the current OTA image as valid if we reached here while in pending verify.
         if let Ok(cur) = self.ota.current_ota_state() {
             if cur == OtaImageState::PendingVerify {
@@ -556,23 +554,24 @@ impl Esp<'_> {
     }
 
     /// Load a config from a specific save slot.
-    pub(crate) async fn load_config_slot(
-        &mut self,
-        idx: usize,
-    ) -> FatResult<String> {
+    pub(crate) async fn load_config_slot(&mut self, idx: usize) -> FatResult<String> {
         match self.savegame.load_slot(idx)? {
             None => bail!("Slot {idx} is empty or invalid"),
-            Some(data) => {
-                Ok(String::from_utf8_lossy(&data).to_string())
-            }
+            Some(data) => Ok(String::from_utf8_lossy(&data).to_string()),
         }
     }
 
     /// Persist a JSON config blob to the next wear-leveling slot.
-    pub(crate) async fn save_config(&mut self, mut config: Vec<u8>) -> FatResult<()> {
+    /// Retries once on flash error.
+    pub(crate) async fn save_config(&mut self, config: Vec<u8>) -> FatResult<()> {
         let timestamp = self.get_time().to_rfc3339();
-        self.savegame.save(config.as_mut_slice(), &timestamp)?;
-        Ok(())
+        match self.savegame.save(config.as_slice(), &timestamp) {
+            Ok(()) => Ok(()),
+            Err(e) => {
+                warn!("First save attempt failed: {e:?}. Retrying...");
+                self.savegame.save(config.as_slice(), &timestamp)
+            }
+        }
     }
 
     /// Delete a specific save slot by erasing it on flash.
@@ -608,7 +607,14 @@ impl Esp<'_> {
                 if to_config_mode {
                     RESTART_TO_CONF = 1;
                 }
-                log(LogMessage::RestartToConfig, RESTART_TO_CONF as u32, 0, "", "").await;
+                log(
+                    LogMessage::RestartToConfig,
+                    RESTART_TO_CONF as u32,
+                    0,
+                    "",
+                    "",
+                )
+                .await;
                 log(
                     LogMessage::LowVoltage,
                     LOW_VOLTAGE_DETECTED as u32,
@@ -702,6 +708,7 @@ impl Esp<'_> {
         let mqtt_timeout = 15000;
         let res = async {
             while !MQTT_CONNECTED_EVENT_RECEIVED.load(Ordering::Relaxed) {
+                crate::hal::PlantHal::feed_watchdog();
                 Timer::after(Duration::from_millis(100)).await;
             }
             Ok::<(), FatError>(())
@@ -720,6 +727,7 @@ impl Esp<'_> {
 
         let res = async {
             while !MQTT_ROUND_TRIP_RECEIVED.load(Ordering::Relaxed) {
+                crate::hal::PlantHal::feed_watchdog();
                 Timer::after(Duration::from_millis(100)).await;
             }
             Ok::<(), FatError>(())