feat: Phase 2 - 성분코드 기반 투약주기/병용약 JOIN 구현

- component_guide 테이블 생성 (PostgreSQL)
- IC2030126 (메벤다졸+프라지퀸텔) 샘플 데이터 입력
- 미리보기 API: apc + component_guide LEFT JOIN
- 모달에 투약주기, 병용약 섹션 추가 (보라색/녹색 강조)

backend/app.py

@@ -6636,14 +6636,22 @@ def api_animal_drug_info_preview():
             with pg_engine.connect() as conn:
                 result = conn.execute(text("""
                     SELECT 
-                        product_name,
-                        company_name,
-                        main_ingredient,
-                        efficacy_effect,
-                        dosage_instructions,
-                        precautions
-                    FROM apc 
-                    WHERE apc = :apc
+                        a.product_name,
+                        a.company_name,
+                        a.main_ingredient,
+                        a.efficacy_effect,
+                        a.dosage_instructions,
+                        a.precautions,
+                        a.component_code,
+                        g.component_name_ko,
+                        g.dosing_interval_adult,
+                        g.dosing_interval_high_risk,
+                        g.dosing_interval_puppy,
+                        g.companion_drugs,
+                        g.contraindication as guide_contraindication
+                    FROM apc a
+                    LEFT JOIN component_guide g ON a.component_code = g.component_code
+                    WHERE a.apc = :apc
                     LIMIT 1
                 """), {'apc': apc})
                 row = result.fetchone()
@@ -6673,6 +6681,17 @@ def api_animal_drug_info_preview():
             text = re.sub(r'\s+(\d+)\)\s*', r'\n  \1) ', text)
             return text.strip()
         
+        # 투약주기 조합
+        dosing_interval = None
+        if row.dosing_interval_adult:
+            parts = []
+            parts.append(f"일반: {row.dosing_interval_adult}")
+            if row.dosing_interval_high_risk:
+                parts.append(f"고위험: {row.dosing_interval_high_risk}")
+            if row.dosing_interval_puppy:
+                parts.append(f"새끼: {row.dosing_interval_puppy}")
+            dosing_interval = '\n'.join(parts)
+        
         return jsonify({
             'success': True,
             'data': {
@@ -6681,7 +6700,13 @@ def api_animal_drug_info_preview():
                 'main_ingredient': row.main_ingredient if row.main_ingredient != 'NaN' else None,
                 'efficacy_effect': format_items(strip_html(row.efficacy_effect)),
                 'dosage_instructions': format_items(strip_html(row.dosage_instructions)),
-                'precautions': format_items(strip_html(row.precautions))
+                'precautions': format_items(strip_html(row.precautions)),
+                # 성분 가이드 (component_guide JOIN)
+                'component_code': row.component_code,
+                'component_name': row.component_name_ko,
+                'dosing_interval': dosing_interval,
+                'companion_drugs': row.companion_drugs,
+                'guide_contraindication': row.guide_contraindication
             }
         })