Adjust timeouts and constants for improved moisture sensor and backup management accuracy

- Increased CAN measurement timeout to 5000ms for reliability.
- Updated `SAVEGAME_SLOT_SIZE` usage in backup handling for consistency.
- Refined moisture sensor frequency thresholds for better sensor calibration (400Hz-70kHz).

Software/MainBoard/rust/src/hal/v4_hal.rs

@@ -391,7 +391,7 @@ impl<'a> BoardInteraction<'a> for V4<'a> {
 
             let mut moistures = Moistures::default();
             let _ = wait_for_can_measurements(&mut twai, &mut moistures)
-                .with_timeout(Duration::from_millis(1000))
+                .with_timeout(Duration::from_millis(5000))
                 .await;
             Ok(moistures)
         })