feat: Add user profile management and password change endpoints

app/schemas/auth.py

@@ -79,3 +79,22 @@ class ApiTokenStatusResponse(BaseModel):
     has_token: bool = Field(..., description="Whether user has an active API token")
     expires_at: datetime | None = Field(None, description="Token expiration timestamp")
     is_expired: bool = Field(..., description="Whether the token is expired")
+
+
+class ChangePasswordRequest(BaseModel):
+    """Schema for password change request."""
+
+    current_password: str | None = Field(None, description="Current password (required if user has existing password)")
+    new_password: str = Field(
+        ...,
+        min_length=8,
+        description="New password (minimum 8 characters)",
+    )
+
+
+class UpdateProfileRequest(BaseModel):
+    """Schema for profile update request."""
+
+    name: str | None = Field(
+        None, min_length=1, max_length=100, description="User display name"
+    )