fix: GSDFC docstring conformance, modernize legacy typing to match signatures; regenerate lib/MCP docs (pydoclint zero)

mail_intake/adapters/base.py

@@ -41,8 +41,12 @@ class MailIntakeAdapter(ABC):
             query (str):
                 Provider-specific query string used to filter messages.
 
+        Returns:
+            Iterator[dict[str, str]]:
+                An iterator over lightweight message reference dictionaries.
+
         Yields:
-            Dict[str, str]:
+            dict[str, str]:
                 Dictionaries containing message and thread identifiers.
 
         Notes:
@@ -73,7 +77,7 @@ class MailIntakeAdapter(ABC):
                 Provider-specific message identifier.
 
         Returns:
-            Dict[str, Any]:
+            dict[str, Any]:
                 Provider-native message payload (e.g., Gmail message JSON structure).
         """
         raise NotImplementedError
@@ -88,7 +92,7 @@ class MailIntakeAdapter(ABC):
                 Provider-specific thread identifier.
 
         Returns:
-            Dict[str, Any]:
+            dict[str, Any]:
                 Provider-native thread payload.
         """
         raise NotImplementedError