feat: Introduce a comprehensive authentication system, including user management, JWT handling, and initial frontend components with Docker support.

backend/auth/password.py

@@ -0,0 +1,32 @@
+# backend/auth/password.py
+# Argon2id password hashing — OWASP 2024 recommended algorithm.
+# Parameters: time_cost=2, memory_cost=64MB, parallelism=2
+
+from argon2 import PasswordHasher
+from argon2.exceptions import VerifyMismatchError, VerificationError
+
+ph = PasswordHasher(
+    time_cost=2,
+    memory_cost=65536,  # 64 MB
+    parallelism=2,
+    hash_len=32,
+    salt_len=16,
+)
+
+
+def hash_password(password: str) -> str:
+    """Hash a password with Argon2id."""
+    return ph.hash(password)
+
+
+def verify_password(password: str, hashed: str) -> bool:
+    """Verify a password against its Argon2id hash."""
+    try:
+        return ph.verify(hashed, password)
+    except (VerifyMismatchError, VerificationError):
+        return False
+
+
+def needs_rehash(hashed: str) -> bool:
+    """Check if hash needs updating (parameters changed)."""
+    return ph.check_needs_rehash(hashed)