Initial MVP skeleton with auth, chat persistence, UI and text LLM integration

backend/app/core/security.py

@@ -0,0 +1,13 @@
+from argon2 import PasswordHasher
+from argon2.exceptions import VerifyMismatchError
+
+ph = PasswordHasher()
+
+def verify_password(plain_password: str, hashed_password: str) -> bool:
+    try:
+        return ph.verify(hashed_password, plain_password)
+    except VerifyMismatchError:
+        return False
+
+def get_password_hash(password: str) -> str:
+    return ph.hash(password)