Implemented content upload app with tests and pre-commit hooks

src/content_automation/interfaces.py

@@ -0,0 +1,12 @@
+from __future__ import annotations
+
+from typing import Protocol
+
+
+class SocialNetworkAdapter(Protocol):
+    """Contract for social network posting adapters."""
+
+    name: str
+
+    def post_media(self, media_url: str, caption: str) -> str:
+        """Publish media and return an external post identifier."""