- add: logout grpc function

- add: logout packet handler
- add: connection state and service for storing connection data
- add: session service calls to auth-service
- fix: compile error on database service due to moved redis cache

packet-service/src/connection_state.rs

@@ -0,0 +1,20 @@
+use std::collections::HashMap;
+
+#[derive(Clone, Debug)]
+pub struct ConnectionState {
+    pub user_id: Option<i32>,
+    pub session_id: Option<String>,
+    pub character_id: Option<i32>,
+    pub additional_data: HashMap<String, String>, // Flexible data storage
+}
+
+impl ConnectionState {
+    pub fn new() -> Self {
+        Self {
+            user_id: None,
+            session_id: None,
+            character_id: None,
+            additional_data: HashMap::new(),
+        }
+    }
+}