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/mcutie_3_0_0/lib.rs

@@ -220,7 +220,7 @@ impl<'t, T: Deref<Target = str> + 't, L: Publishable + 't, const S: usize>
                 username: self.username,
                 password: self.password,
                 subscriptions: self.subscriptions,
-                keep_alive
+                keep_alive,
             },
         )
     }