Show badges for Alumni and Advisors

Right now we don't show badges for alumni and advisors due to the nature of it requiring an ldap sync.

1. Call LDAP on first misc signatures of a packet to collect roles
2. On subsequent signatures, check to see if they've signed another packet, if so, pull roles from previous signature to avoid ldap call
3. Update `ldap-sync` to update roles on all transitions

(We may also want to move in the schema a `roles` table so that we only pull the data once per person overall)

首先追踪 issue 中提到的数据包签名处理和 `ldap-sync` 入口点。确认当前如何获取和持久化角色，然后验证首次签名会查询 LDAP，后续签名会复用之前的角色，并且角色转换会更新所有受影响的记录；任何 schema 变更都应单独评估。

由索引模型根据 Issue 内容生成。