refactored the docs

docs/Sequence Diagram.mmd

@@ -0,0 +1,34 @@
+─```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)
+```