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/app/modules/users/schemas.py

@@ -0,0 +1,34 @@
+from pydantic import BaseModel, EmailStr, Field, field_validator
+
+from app.core.password_policy import validate_password_strength
+
+
+class UserOut(BaseModel):
+    id: str
+    email: EmailStr
+    role: str
+    status: str
+
+
+class UserProfileOut(BaseModel):
+    display_name: str
+    avatar_url: str | None = None
+
+
+class UserMeOut(BaseModel):
+    user: UserOut
+    profile: UserProfileOut
+
+
+class UserPatchIn(BaseModel):
+    display_name: str | None = Field(default=None, min_length=1, max_length=120)
+
+
+class PasswordChangeIn(BaseModel):
+    current_password: str
+    new_password: str = Field(min_length=8)
+
+    @field_validator("new_password")
+    @classmethod
+    def password_policy(cls, value: str) -> str:
+        return validate_password_strength(value)