Migrate serialization from Bincode to Postcard

- Replaced Bincode with Postcard for serialization/deserialization across configs and save operations.
- Simplified struct derives by removing `bincode`-specific traits.
- Updated `Cargo.toml` and `Cargo.lock` to include `postcard` and dependencies.
- Added padding stripping for deserialization and improved error handling.
- Adjusted serialization logic in `savegame_manager.rs` and related modules.

Software/MainBoard/rust/src/config.rs

@@ -1,10 +1,9 @@
 use crate::hal::PLANT_COUNT;
 use crate::plant_state::PlantWateringMode;
 use alloc::string::{String, ToString};
-use bincode::{Decode, Encode};
 use serde::{Deserialize, Serialize};
 
-#[derive(Serialize, Deserialize, Clone, Debug, PartialEq, Encode, Decode)]
+#[derive(Serialize, Deserialize, Clone, Debug, PartialEq)]
 #[serde(default)]
 pub struct NetworkConfig {
     pub ap_ssid: String,
@@ -31,7 +30,7 @@ impl Default for NetworkConfig {
     }
 }
 
-#[derive(Serialize, Deserialize, Clone, Debug, PartialEq, Encode, Decode)]
+#[derive(Serialize, Deserialize, Clone, Debug, PartialEq)]
 #[serde(default)]
 pub struct NightLampConfig {
     pub enabled: bool,
@@ -54,7 +53,7 @@ impl Default for NightLampConfig {
     }
 }
 
-#[derive(Serialize, Deserialize, Clone, Debug, PartialEq, Encode, Decode)]
+#[derive(Serialize, Deserialize, Clone, Debug, PartialEq)]
 #[serde(default)]
 pub struct TankConfig {
     pub tank_sensor_enabled: bool,
@@ -79,20 +78,20 @@ impl Default for TankConfig {
     }
 }
 
-#[derive(Serialize, Deserialize, Clone, Debug, PartialEq, Default, Encode, Decode)]
+#[derive(Serialize, Deserialize, Clone, Debug, PartialEq, Default)]
 pub enum BatteryBoardVersion {
     #[default]
     Disabled,
     WchI2cSlave,
 }
-#[derive(Serialize, Deserialize, Clone, Debug, PartialEq, Default, Encode, Decode)]
+#[derive(Serialize, Deserialize, Clone, Debug, PartialEq, Default)]
 pub enum BoardVersion {
     Initial,
     #[default]
     V4,
 }
 
-#[derive(Serialize, Deserialize, Clone, Debug, PartialEq, Default, Encode, Decode)]
+#[derive(Serialize, Deserialize, Clone, Debug, PartialEq, Default)]
 pub struct BoardHardware {
     pub board: BoardVersion,
     pub battery: BatteryBoardVersion,
@@ -100,7 +99,7 @@ pub struct BoardHardware {
     pub pump_corrosion_protection: bool,
 }
 
-#[derive(Serialize, Deserialize, Clone, Debug, PartialEq, Default, Encode, Decode)]
+#[derive(Serialize, Deserialize, Clone, Debug, PartialEq, Default)]
 #[serde(default)]
 pub struct PlantControllerConfig {
     pub hardware: BoardHardware,
@@ -111,7 +110,7 @@ pub struct PlantControllerConfig {
     pub timezone: Option<String>,
 }
 
-#[derive(Serialize, Deserialize, Clone, Debug, PartialEq, Encode, Decode)]
+#[derive(Serialize, Deserialize, Clone, Debug, PartialEq)]
 #[serde(default)]
 pub struct PlantConfig {
     pub mode: PlantWateringMode,