Add a website chatbot with memory and live web search

flowchart TD trig>"visitor sends chat message"]:::trig s0["read message and history"]:::task s1["check if answer is known"]:::task s2["write conversational reply"]:::task trig --> s0 s0 --> s1 gx{"× does it already know the answer"}:::gate s1 --> gx p00["use existing knowledge"]:::task gx -->|"already knows"| p00 p10["search the web"]:::task gx -->|"needs lookup"| p10 jn{"○ compose the reply"}:::gate p00 --> jn p10 --> jn jn --> s2 out[/"instant answer shown in chat"/]:::out pay{{"fewer visitors leave unanswered"}}:::pay s2 --> out out --> pay classDef task fill:#e7f6fe,stroke:#34b8f0,color:#2c2a29 classDef svc fill:#f6f8fa,stroke:#7c8795,color:#2c2a29 classDef mi fill:#e7f6fe,stroke:#0079a8,color:#2c2a29,stroke-width:2px classDef human fill:#fff,stroke:#0079a8,color:#0079a8 classDef store fill:#f6f8fa,stroke:#0079a8,color:#2c2a29 classDef trig fill:#00a4eb,stroke:#0079a8,color:#fff,font-weight:bold classDef trigtime fill:#00a4eb,stroke:#0079a8,color:#fff,font-weight:bold classDef trigdata fill:#8ad4f5,stroke:#0079a8,color:#06314c,font-weight:bold classDef gate fill:#fff,stroke:#e8a23d,color:#6b4708,font-weight:bold classDef out fill:#1f9d6b,stroke:#167a53,color:#fff,font-weight:bold classDef pay fill:#06314c,stroke:#021f33,color:#fff