standardize packaging, tooling, docs, CI, and licensing

mail_intake/credentials/store.pyi

@@ -1,11 +1,11 @@
 from abc import ABC, abstractmethod
-from typing import Generic, Optional, TypeVar
+from typing import Generic, TypeVar
 
 T = TypeVar("T")
 
 class CredentialStore(ABC, Generic[T]):
     @abstractmethod
-    def load(self) -> Optional[T]: ...
+    def load(self) -> T | None: ...
     @abstractmethod
     def save(self, credentials: T) -> None: ...
     @abstractmethod