Add logic to prevent multiple births for mothers in a single day: Implemented a new SQL query to check if a mother has already given birth today. Updated the FalukantFamilyWorker and UserCharacterWorker to utilize this check, enhancing the birth registration process and ensuring compliance with the new birth rule.

src/worker/sql.rs

@@ -3886,6 +3886,16 @@ pub const QUERY_INSERT_CHILD_RELATION_LOVER: &str = r#"
     );
 "#;
 
+/// Realismus-Regel: pro Mutter maximal eine Geburt pro Kalendertag.
+pub const QUERY_HAS_MOTHER_BIRTH_TODAY: &str = r#"
+    SELECT EXISTS (
+        SELECT 1
+          FROM falukant_data.child_relation cr
+         WHERE cr.mother_character_id = $1::int
+           AND cr.created_at::date = CURRENT_DATE
+    ) AS has_birth_today;
+"#;
+
 // --- Produktionszertifikat (Daemon Daily, Spec: Produktionszertifikate) ---
 
 /// Ein Spielercharakter pro Falukant-User (bei mehreren lebenden: **höchste** `character.id`,