Rafforza i requisiti password con regole di complessità di mercato.

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

backend/app/services/users/change_password.rb

@@ -23,15 +23,19 @@ module Users
         return Result.new(ok?: false, error: :current_incorrect)
       end
 
-      if @password.blank? || @password.length < 8
-        return Result.new(ok?: false, error: :too_short)
-      end
-
       if @password != @password_confirmation
         return Result.new(ok?: false, error: :mismatch)
       end
 
-      @user.update!(password: @password)
+      if (code = PasswordComplexity.violation(@password))
+        return Result.new(ok?: false, error: code == :blank ? :too_short : code)
+      end
+
+      unless @user.update(password: @password)
+        complexity_error = @user.errors.details[:password]&.any? { |d| d[:error] == :complexity }
+        return Result.new(ok?: false, error: complexity_error ? :too_weak : :too_short)
+      end
+
       @user.clear_password_reset!
       Result.new(ok?: true)
     end