Implement election candidate table readiness check in character deletion process: Added a new SQL query to verify the existence of the election candidate table before attempting to delete associated records. Updated the deletion logic in both EventsWorker and UserCharacterWorker to conditionally execute the deletion of election candidates based on the table's readiness, improving robustness and preventing errors in environments where the table may not exist.

src/worker/sql.rs

@@ -2577,6 +2577,16 @@ pub const QUERY_DELETE_ELECTION_CANDIDATE: &str = r#"
          WHERE character_id = $1;
 "#;
 
+/// Legacy-/Migrationsschutz: Tabelle existiert nicht in allen Umgebungen.
+pub const QUERY_ELECTION_CANDIDATE_TABLE_READY: &str = r#"
+    SELECT EXISTS (
+        SELECT 1
+          FROM information_schema.tables
+         WHERE table_schema = 'falukant_data'
+           AND table_name = 'election_candidate'
+    ) AS ready;
+"#;
+
 pub const QUERY_GET_STOCK_TYPE_ID: &str = r#"
 SELECT id FROM falukant_type.stock WHERE label_tr = $1 LIMIT 1;
 "#;