fix(esn): pom.xml finalName 패턴 수정 + schema.sql esn_audit_log 테이블 추가

- pom.xml: finalName esn → esn-1.0.0 (deploy_server.py esn-*.jar 패턴 일치)
- schema.sql: esn_audit_log 테이블 추가 (감사 로그)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/pom.xml

@@ -72,6 +72,6 @@
         </configuration>
       </plugin>
     </plugins>
-    <finalName>esn</finalName>
+    <finalName>esn-1.0.0</finalName>
   </build>
 </project>

backend/src/main/resources/db/schema.sql

@@ -260,3 +260,20 @@ INSERT INTO esn_product (tenant_code, store_id, product_code, product_name, cate
 SELECT 'EMART', s.id, 'P-001', '신라면', '라면/면류', 850, 800
 FROM esn_store s WHERE s.store_code = 'EM-001' LIMIT 1
 ON CONFLICT DO NOTHING;
+
+-- ── 감사 로그 ─────────────────────────────────────────────────────────────────
+CREATE TABLE IF NOT EXISTS esn_audit_log (
+    id          BIGSERIAL PRIMARY KEY,
+    tenant_code VARCHAR(20),
+    username    VARCHAR(200),
+    action      VARCHAR(200) NOT NULL,
+    resource    VARCHAR(200),
+    resource_id VARCHAR(100),
+    detail      TEXT,
+    ip_address  VARCHAR(50),
+    user_agent  VARCHAR(500),
+    success     BOOLEAN DEFAULT TRUE,
+    created_at  TIMESTAMP DEFAULT NOW()
+);
+CREATE INDEX IF NOT EXISTS idx_audit_created ON esn_audit_log(created_at DESC);
+CREATE INDEX IF NOT EXISTS idx_audit_tenant ON esn_audit_log(tenant_code, created_at DESC);