feat: use ClassifiedAdTitle value object for ClassifiedAd.title

domain/marketplace/classified_ad_title.py

@@ -0,0 +1,10 @@
+from dataclasses import dataclass
+
+
+@dataclass(frozen=True)
+class ClassifiedAdTitle:
+    title: str
+
+    def __post_init__(self):
+        if len(self.title) > 100:
+            raise ValueError(f"Title cannot be longer than 100 characters: {self.title}")