Rifiuta il riuso della password attuale in cambio e reset.

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/spec/requests/account_spec.rb

@@ -73,6 +73,19 @@ RSpec.describe "Account API", type: :request do
       expect(JSON.parse(response.body)["error"]).to match(/3 of/i)
       expect(user.reload.authenticate("Password123")).to be_truthy
     end
+
+    it "rejects reusing the current password" do
+      patch "/api/v1/account/password",
+            params: {
+              current_password: "Password123",
+              password: "Password123",
+              password_confirmation: "Password123"
+            },
+            headers: auth_headers
+      expect(response).to have_http_status(:unprocessable_entity)
+      expect(JSON.parse(response.body)["error"]).to match(/different/i)
+      expect(user.reload.authenticate("Password123")).to be_truthy
+    end
   end
 
   describe "POST /api/v1/auth/password/forgot" do