Implement character death handling and periodic checks: Add logic to process characters with health <= 0 in EventsWorker and UserCharacterWorker, including immediate death handling during health updates and a scheduled death check every 12 hours. Introduce a new SQL query to retrieve characters with zero health.

src/worker/sql.rs

@@ -587,6 +587,11 @@ pub const QUERY_GET_USERS_TO_UPDATE: &str = r#"
         WHERE user_id IS NOT NULL;
 "#;
 
+pub const QUERY_GET_CHARACTERS_ZERO_HEALTH: &str = r#"
+        SELECT id FROM falukant_data."character"
+        WHERE user_id IS NOT NULL AND health <= 0;
+"#;
+
 // politics worker queries
 pub const QUERY_COUNT_OFFICES_PER_REGION: &str = r#"
         WITH