fix: 使用HS256签名，与旧门户保持一致

seecoder-portal-server/src/main/java/cn/seecoder/seecoderportalserver/security/jwt/TokenProvider.java

@@ -70,7 +70,7 @@ public class TokenProvider {
                 .claim(AUTHORITIES_KEY, authorities)
                 .claim(USER_DETAIL_KEY,
                         userMapper.domainToUserVO((DomainUserDetails) authentication.getPrincipal()))
-                .signWith(key, SignatureAlgorithm.HS512)
+                .signWith(key, SignatureAlgorithm.HS256)
                 .compact();
     }