fix(security): CRITICAL 보안 이슈 13건 일괄 수정

- SEC-42: JWT algorithm HS256 명시 (sign 5곳, verify 3곳)
- SEC-44: MariaDB/PhpMyAdmin 포트 127.0.0.1 바인딩
- SEC-29: escHtml = escapeHtml alias 추가 (XSS 방지)
- SEC-39: Python Dockerfile 4개 non-root user + chown
- SEC-43: deploy-remote.sh 삭제 (평문 비밀번호 포함)
- SEC-11,12: SQL SET ? → 명시적 컬럼 whitelist + IN절 parameterized
- QA-34: vacation approveRequest/cancelRequest 트랜잭션 래핑
- SEC-32,34: material_comparison.py 5개 엔드포인트 인증 + confirmed_by
- SEC-33: files.py 17개 미인증 엔드포인트 인증 추가
- SEC-37: chatbot 프롬프트 인젝션 방어 (sanitize + XML 구분자)
- SEC-38: fastapi-bridge 프록시 JWT 검증 + 캐시 키 user_id 포함
- SEC-58/QA-98: monthly-comparison API_BASE_URL 수정 + 401 처리
- SEC-61: monthlyComparisonModel SELECT FOR UPDATE 추가
- SEC-63: proxyInputController 에러 메시지 노출 제거
- QA-103: pageAccessRoutes error→message 통일
- SEC-62: tbm-create onclick 인젝션 → data-attribute event delegation
- QA-99: tbm-mobile/create 캐시 버스팅 갱신
- QA-100,101: ESC 키 리스너 cleanup 추가

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

sso-auth-service/controllers/authController.js

@@ -83,11 +83,11 @@ async function login(req, res, next) {
     await userModel.updateLastLogin(user.user_id);
 
     const payload = createTokenPayload(user);
-    const access_token = jwt.sign(payload, JWT_SECRET, { expiresIn: JWT_EXPIRES_IN });
+    const access_token = jwt.sign(payload, JWT_SECRET, { expiresIn: JWT_EXPIRES_IN, algorithm: 'HS256' });
     const refresh_token = jwt.sign(
       { user_id: user.user_id, type: 'refresh' },
       JWT_REFRESH_SECRET,
-      { expiresIn: JWT_REFRESH_EXPIRES_IN }
+      { expiresIn: JWT_REFRESH_EXPIRES_IN, algorithm: 'HS256' }
     );
 
     // SSO 쿠키는 클라이언트(login.html)에서 domain=.technicalkorea.net으로 설정
@@ -159,7 +159,7 @@ async function loginForm(req, res, next) {
     await userModel.updateLastLogin(user.user_id);
 
     const payload = createTokenPayload(user);
-    const access_token = jwt.sign(payload, JWT_SECRET, { expiresIn: JWT_EXPIRES_IN });
+    const access_token = jwt.sign(payload, JWT_SECRET, { expiresIn: JWT_EXPIRES_IN, algorithm: 'HS256' });
 
     res.json({
       access_token,
@@ -187,7 +187,8 @@ async function validate(req, res, next) {
       return res.status(401).json({ success: false, error: '토큰이 필요합니다' });
     }
 
-    const decoded = jwt.verify(token, JWT_SECRET);
+    // TODO: issuer/audience 클레임 검증 추가 검토
+    const decoded = jwt.verify(token, JWT_SECRET, { algorithms: ['HS256'] });
     const user = await userModel.findById(decoded.user_id || decoded.id);
     if (!user || !user.is_active) {
       return res.status(401).json({ success: false, error: '유효하지 않은 사용자입니다' });
@@ -229,7 +230,7 @@ async function me(req, res, next) {
       return res.status(401).json({ detail: 'Not authenticated' });
     }
 
-    const decoded = jwt.verify(token, JWT_SECRET);
+    const decoded = jwt.verify(token, JWT_SECRET, { algorithms: ['HS256'] });
     const user = await userModel.findById(decoded.user_id || decoded.id);
     if (!user || !user.is_active) {
       return res.status(401).json({ detail: 'User not found or inactive' });
@@ -261,7 +262,7 @@ async function refresh(req, res, next) {
       return res.status(400).json({ success: false, error: 'Refresh 토큰이 필요합니다' });
     }
 
-    const decoded = jwt.verify(refresh_token, JWT_REFRESH_SECRET);
+    const decoded = jwt.verify(refresh_token, JWT_REFRESH_SECRET, { algorithms: ['HS256'] });
     if (decoded.type !== 'refresh') {
       return res.status(401).json({ success: false, error: '유효하지 않은 Refresh 토큰입니다' });
     }
@@ -272,11 +273,11 @@ async function refresh(req, res, next) {
     }
 
     const payload = createTokenPayload(user);
-    const access_token = jwt.sign(payload, JWT_SECRET, { expiresIn: JWT_EXPIRES_IN });
+    const access_token = jwt.sign(payload, JWT_SECRET, { expiresIn: JWT_EXPIRES_IN, algorithm: 'HS256' });
     const new_refresh_token = jwt.sign(
       { user_id: user.user_id, type: 'refresh' },
       JWT_REFRESH_SECRET,
-      { expiresIn: JWT_REFRESH_EXPIRES_IN }
+      { expiresIn: JWT_REFRESH_EXPIRES_IN, algorithm: 'HS256' }
     );
 
     res.json({