─```mermaid
sequenceDiagram
    autonumber
    actor A as Advisor
    participant UI as UI (S3/CloudFront)
    participant F as Fusion 
    participant TK as tokenize (on-prem)
    participant PR as Presidio (private)
    participant V as Vault (DynamoDB)
    participant RT as AgentCore Runtime + Bedrock (cloud)
    participant GW as AgentCore Gateway (cloud)
    participant RG as RAG Lambda (on-prem)
    participant RS as restore (on-prem)

    A->>UI: query with 王小明 + A123456789
    UI->>F: POST {query}
    F->>TK: {query}
    TK->>PR: POST /analyze
    PR-->>TK: typed findings
    TK->>V: write token to PII map (session)
    TK-->>F: deidentified_prompt (CUST_*)
    F->>RT: {prompt: CUST_*}
    Note over RT,GW: cloud sees TOKENS only
    RT->>GW: tools/call get_customer_activity_summary(CUST_*)
    GW->>RG: invoke (SigV4)
    RG->>V: resolve token to customer_id
    RG-->>RT: de-identified evidence package
    RT-->>F: talking points (tokens only)
    F->>RS: {session_id, text}
    RS->>V: lookup session tokens
    RS-->>F: final (王小明 restored)
    F-->>UI: {final, deidentified_prompt, agent_tokenized}
    UI-->>A: split view (restored vs tokenized)
```