feat: add scriptable housekeeper rule engine

src/ccma/rules/scripts/birthdate_check.py

@@ -0,0 +1,41 @@
+from ccma.domain.dates import DateValidationError, validate_member_dates
+from ccma.rules.api import RuleContext, task
+
+RULE_ID = "birthdate-check"
+ORDER = 10
+
+
+def evaluate(context: RuleContext):
+    member = context.member
+    if not member.birth_date.strip():
+        return [
+            task(
+                rule_id=RULE_ID,
+                member=member,
+                key_suffix="missing",
+                severity="warning",
+                title=f"{member.display_name}: Geburtsdatum fehlt",
+                detail="Das Geburtsdatum muss in der Mitgliederakte ergänzt werden.",
+                code="missing_birth_date",
+            )
+        ]
+    try:
+        validate_member_dates(
+            birth_date=member.birth_date,
+            accepted_at=member.accepted_at,
+            membership_started_at=member.membership_started_at,
+            today=context.today,
+        )
+    except DateValidationError as exc:
+        return [
+            task(
+                rule_id=RULE_ID,
+                member=member,
+                key_suffix="invalid",
+                severity="error",
+                title=f"{member.display_name}: Ungültige Datumsangabe",
+                detail=str(exc),
+                code="invalid_member_dates",
+            )
+        ]
+    return []