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/sql.rs

@@ -743,6 +743,12 @@ pub const QUERY_SET_CHARACTER_USER: &str = r#"
 UPDATE falukant_data.character SET user_id = $1, updated_at = NOW() WHERE id = $2;
 "#;
 
+// Erben-Logik: erst alte User-Zuordnung lösen (für Unique-Constraints auf character.user_id),
+// dann den Erben übernehmen lassen.
+pub const QUERY_CLEAR_CHARACTER_USER: &str = r#"
+UPDATE falukant_data.character SET user_id = NULL, updated_at = NOW() WHERE id = $1;
+"#;
+
 pub const QUERY_GET_CURRENT_MONEY: &str = r#"
 SELECT money FROM falukant_data.falukant_user WHERE id = $1;
 "#;