feat(gyeol): Q4Step (비용 라디오 6) + Q5Step (도구 라디오 8 + 만족도 1-5)

- Q4: 라디오 패턴 재사용 (Q2와 동일 스타일)
- Q5: 두 입력 한 화면 — 도구 라디오 + 만족도 1-5 버튼 그리드
- 둘 다 선택 시 다음 활성

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

app/gyeol/components/Q4Step.tsx

@@ -0,0 +1,55 @@
+'use client';
+
+import { useState } from 'react';
+import { COST_RANGES } from '@/lib/survey/questions';
+import type { SurveyResponse } from '@/lib/survey/types';
+import QuestionLayout from './QuestionLayout';
+
+interface Props {
+  initial: Partial<SurveyResponse>;
+  onPrev: () => void;
+  onNext: (partial: Partial<SurveyResponse>) => void;
+}
+
+export default function Q4Step({ initial, onPrev, onNext }: Props) {
+  const [value, setValue] = useState(initial.cost_range ?? '');
+
+  return (
+    <QuestionLayout
+      step="q4"
+      onPrev={onPrev}
+      onNext={() => onNext({ cost_range: value })}
+      nextDisabled={!value}
+    >
+      <div className="space-y-2">
+        {COST_RANGES.map((option) => (
+          <label
+            key={option}
+            className={`flex items-center gap-3 px-4 py-3.5 rounded-xl border cursor-pointer transition ${
+              value === option
+                ? 'border-violet-400 bg-violet-400/10'
+                : 'border-white/15 bg-white/[0.02] hover:border-white/30'
+            }`}
+          >
+            <input
+              type="radio"
+              name="cost_range"
+              value={option}
+              checked={value === option}
+              onChange={() => setValue(option)}
+              className="sr-only"
+            />
+            <span
+              className={`w-4 h-4 rounded-full border-2 flex items-center justify-center flex-shrink-0 ${
+                value === option ? 'border-violet-400' : 'border-white/30'
+              }`}
+            >
+              {value === option && <span className="w-2 h-2 rounded-full bg-violet-400" />}
+            </span>
+            <span className="text-sm text-white">{option}</span>
+          </label>
+        ))}
+      </div>
+    </QuestionLayout>
+  );
+}