feat: add server selection and order flow after recommendation

- Add 'selecting' and 'ordering' status to ServerSession
- Add lastRecommendation field to store recommendation results
- Keep session alive after recommendation (don't delete immediately)
- Add selection pattern matching (1번, 첫번째, 1번 선택 등)
- Add order confirmation message with inline buttons
- Add server_order/server_cancel callback handlers
- Add ServerOrderKeyboardData type for button data

Flow: recommend → select number → confirm with buttons → order/cancel

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/tools/server-tool.ts

@@ -259,6 +259,51 @@ async function callCloudOrchestratorApi(
   }
 }
 
+// 추천 데이터 조회 (포맷팅 없이 원본 반환)
+export async function getRecommendationData(
+  args: {
+    tech_stack: string[];
+    expected_users: number;
+    use_case: string;
+    traffic_pattern?: string;
+    region_preference?: string[];
+    budget_limit?: number;
+    lang?: string;
+  },
+  env?: Env
+): Promise<RecommendResponse | null> {
+  const { tech_stack, expected_users, use_case, traffic_pattern, region_preference, budget_limit, lang } = args;
+
+  // 언어 자동 감지
+  const detectedLang = lang || detectLanguage(use_case);
+
+  // CDN 캐시 히트율 추정
+  const cdnCacheHitRate = estimateCdnCacheHitRate(tech_stack, use_case);
+
+  // API 요청 body 구성
+  const requestBody: Record<string, unknown> = {
+    tech_stack,
+    expected_users,
+    use_case,
+    lang: detectedLang,
+  };
+
+  if (traffic_pattern) requestBody.traffic_pattern = traffic_pattern;
+  if (region_preference) requestBody.region_preference = region_preference;
+  if (budget_limit) requestBody.budget_limit = budget_limit;
+  if (cdnCacheHitRate !== null) requestBody.cdn_cache_hit_rate = cdnCacheHitRate;
+
+  // API 호출
+  const result = await callCloudOrchestratorApi('/api/recommend', 'POST', requestBody, env);
+
+  if (isErrorResult(result)) {
+    logger.error('추천 데이터 조회 실패', new Error(result.error));
+    return null;
+  }
+
+  return result as RecommendResponse;
+}
+
 // 서버 추천 결과 포맷팅 (필수 정보만)
 // __DIRECT__ 마커로 AI 재해석 없이 바로 반환
 function formatRecommendations(data: RecommendResponse): string {