Update admin theme/layout and refresh README details.

Align the project baseline with the latest admin interface styling and layout structure while documenting setup and usage updates in README.

apps/api/tests/modules/auth/test_password_policy.py

@@ -0,0 +1,12 @@
+import pytest
+
+from app.core.password_policy import validate_password_strength
+
+
+def test_password_policy_accepts_valid_password():
+    assert validate_password_strength("Valid123") == "Valid123"
+
+
+def test_password_policy_rejects_weak_password():
+    with pytest.raises(ValueError, match="uppercase letter"):
+        validate_password_strength("valid123")