Refactor SQL queries into centralized module

- Moved various SQL query strings from individual worker files into a new `sql.rs` module for better organization and reusability.
- Updated `events.rs`, `underground.rs`, and `weather.rs` to use the centralized SQL queries.
- Removed redundant query definitions from `events.rs`, `underground.rs`, and `weather.rs`.

src/worker/underground.rs

@@ -11,6 +11,7 @@ use std::sync::Arc;
 use std::time::Duration;
 
 use super::base::{BaseWorker, Worker, WorkerState};
+use crate::worker::sql::QUERY_UPDATE_MONEY;
 
 pub struct UndergroundWorker {
     base: BaseWorker,
@@ -118,10 +119,7 @@ const Q_SELECT_FALUKANT_USER: &str = r#"
      LIMIT 1;
 "#;
 
-// Query für Geldänderungen (lokale Variante von BaseWorker::change_falukant_user_money)
-const QUERY_UPDATE_MONEY: &str = r#"
-    SELECT falukant_data.update_money($1, $2, $3);
-"#;
+// Use centralized QUERY_UPDATE_MONEY from src/worker/sql.rs
 
 impl UndergroundWorker {
     pub fn new(pool: ConnectionPool, broker: MessageBroker) -> Self {