refactor: some restructuring

- move structs inside `sr_tools.rs` into individual file
- implement in-game equip handler (relic & lightcone)

common/src/structs/persistent.rs

@@ -0,0 +1,60 @@
+use std::collections::BTreeMap;
+
+use serde::{Deserialize, Serialize};
+
+use super::{
+    avatar::MultiPathAvatar,
+    scene::{Position, Scene},
+};
+
+// #[derive(Serialize, Deserialize, Clone, Debug, Copy, PartialEq, Eq, Default)]
+// #[repr(u32)]
+// pub enum AllowedLanguages {
+//     #[default]
+//     En,
+//     Jp,
+//     Kr,
+//     Cn,
+// }
+
+// impl FromStr for AllowedLanguages {
+//     type Err = ();
+
+//     fn from_str(input: &str) -> Result<AllowedLanguages, Self::Err> {
+//         match input {
+//             "en" => Ok(AllowedLanguages::En),
+//             "kr" => Ok(AllowedLanguages::Kr),
+//             "jp" => Ok(AllowedLanguages::Jp),
+//             "cn" => Ok(AllowedLanguages::Cn),
+//             _ => Ok(AllowedLanguages::En),
+//         }
+//     }
+// }
+
+#[derive(Debug, Serialize, Deserialize)]
+pub struct Persistent {
+    #[serde(default)]
+    pub lineups: BTreeMap<u32, u32>,
+    #[serde(default)]
+    pub position: Position,
+    #[serde(default)]
+    pub scene: Scene,
+    pub main_character: MultiPathAvatar,
+    pub march_type: MultiPathAvatar,
+    // pub game_language: AllowedLanguages,
+    // pub voice_language: AllowedLanguages,
+}
+
+impl Default for Persistent {
+    fn default() -> Self {
+        Self {
+            lineups: BTreeMap::from([(0, 1313), (1, 1006), (2, 8001), (3, 1405)]),
+            position: Default::default(),
+            main_character: MultiPathAvatar::FemaleRememberance,
+            scene: Default::default(),
+            march_type: MultiPathAvatar::MarchHunt,
+            // game_language: AllowedLanguages::En,
+            // voice_language: AllowedLanguages::Jp,
+        }
+    }
+}