Add character user clearing logic in EventsWorker: Implement a new SQL query to clear the user association from a deceased character before assigning a new heir. This ensures compliance with unique constraints and prevents errors during user reassignment. Enhance error handling and logging for better debugging.

src/worker/user_character.rs

@@ -29,6 +29,7 @@ use crate::worker::sql::{
     QUERY_GET_HEIR,
     QUERY_RANDOM_HEIR,
     QUERY_SET_CHARACTER_USER,
+    QUERY_CLEAR_CHARACTER_USER,
     QUERY_UPDATE_USER_MONEY,
     QUERY_GET_FALUKANT_USER_ID,
     QUERY_AUTOBATISM,
@@ -608,6 +609,8 @@ impl UserCharacterWorker {
         }
 
         if heir_id > 0 {
+            // Erst die alte Zuordnung lösen (Unique-Constraint safety), dann den Erben zuweisen.
+            self.clear_character_user(character_id)?;
             self.set_new_character(falukant_user_id, heir_id)?;
         }
         self.set_new_money(falukant_user_id, new_money)?;
@@ -685,6 +688,18 @@ impl UserCharacterWorker {
         Ok(())
     }
 
+    fn clear_character_user(&mut self, deceased_character_id: i32) -> Result<(), DbError> {
+        let mut conn = self
+            .base
+            .pool
+            .get()
+            .map_err(|e| DbError::new(format!("DB-Verbindung fehlgeschlagen: {e}")))?;
+
+        conn.prepare("clear_character_user", QUERY_CLEAR_CHARACTER_USER)?;
+        conn.execute("clear_character_user", &[&deceased_character_id])?;
+        Ok(())
+    }
+
     fn set_new_money(&mut self, falukant_user_id: i32, new_amount: f64) -> Result<(), DbError> {
         let mut conn = self
             .base