refactor(config): abstract config storage and enable dependency injection

Abstract the configuration storage mechanism to allow using custom
configurations, such as in-memory setups, when using the tool as
a library. This aligns the configuration architecture with the
session cache abstraction.

- Define ConfigInterface protocol and InMemoryConfig class
- Make CacheFile, InMemoryCache, ConfigFile, and InMemoryConfig
  explicitly inherit their interfaces
- Update MdrsService and MdrsClient to accept customizable
  config_class and config instances
- Add validation to check remote parameter consistency in
  create_connection
- Remove unused imports across command files

mdrsclient/client.py

@@ -4,6 +4,7 @@ from unicodedata import normalize
 
 from mdrsclient.api import DoiApi, FilesApi, FoldersApi, LaboratoriesApi, UsersApi
 from mdrsclient.cache import CacheInterface
+from mdrsclient.config import ConfigInterface
 from mdrsclient.connection import MDRSConnection
 from mdrsclient.exceptions import IllegalArgumentException, MDRSException, UnauthorizedException, UnexpectedException
 from mdrsclient.models import File, Folder, Laboratory, Token, User
@@ -14,12 +15,14 @@ from mdrsclient.services import MdrsService
 class MdrsClient(MdrsService):
     """Service layer client for MDRS."""
 
-    def __init__(self, connection: MDRSConnection):
-        super().__init__(connection)
+    def __init__(self, connection: MDRSConnection, config_class: type[ConfigInterface] | None = None):
+        super().__init__(connection, config_class)
 
     @classmethod
-    def from_remote(cls, remote: str, cache: CacheInterface | None = None) -> "MdrsClient":
-        return cls(cls.create_connection(remote, cache))
+    def from_remote(
+        cls, remote: str, cache: CacheInterface | None = None, config: ConfigInterface | None = None
+    ) -> "MdrsClient":
+        return cls(cls.create_connection(remote, cache, config))
 
     def mkdir(self, remote_path: str) -> None:
         remote, laboratory_name, r_path = self.parse_remote_host_with_path(remote_path)
@@ -208,36 +211,28 @@ class MdrsClient(MdrsService):
         return f"mdrs {__version__}"
 
     def config_create(self, remote: str, url: str) -> None:
-        from mdrsclient.config import ConfigFile
-
         remote = self.parse_remote_host(remote)
-        config = ConfigFile(remote)
+        config = self.config_class(remote)
         if config.url is not None:
             raise IllegalArgumentException(f"Remote host `{remote}` is already exists.")
         else:
             config.url = url
 
     def config_update(self, remote: str, url: str) -> None:
-        from mdrsclient.config import ConfigFile
-
         remote = self.parse_remote_host(remote)
-        config = ConfigFile(remote)
+        config = self.config_class(remote)
         if config.url is None:
             raise IllegalArgumentException(f"Remote host `{remote}` is not exists.")
         else:
             config.url = url
 
     def config_list(self) -> list:
-        from mdrsclient.config import ConfigFile
-
-        config = ConfigFile("")
+        config = self.config_class("")
         return config.list()
 
     def config_delete(self, remote: str) -> None:
-        from mdrsclient.config import ConfigFile
-
         remote = self.parse_remote_host(remote)
-        config = ConfigFile(remote)
+        config = self.config_class(remote)
         if config.url is None:
             raise IllegalArgumentException(f"Remote host `{remote}` is not exists.")
         else: