协议观察、目录与 Contacts 投影
sequenceDiagram participant B as Protocol backend participant D as PeerDirectory participant C as ContactService participant S as Stores participant UI as Contacts UI B->>D: record identity + facts D->>C: observed record C->>S: persist UI->>C: query active protocol C-->>UI: contacts/nearby/ignored UI->>C: save, ignore or verify C->>S: commit local relation