feat: production-ready cloud deployment with single-port reverse proxy

Implement entity-level PII remediation controls (BLOCK, MASK, REWRITE, IGNORE) for specific PII types in the Streamlit UI and proxy backend

Integrate DeBERTa-v3 PII guardrail, rename guardrail modules, fix ModelResponse item assignment error, and display guardrailed query in Streamlit UI

feat: implement stacked UI layout, individualized model settings, PII renaming, session history logs, and customizable regex guardrails

feat: integrate Streamlit frontend dashboard, configure dynamic proxy URL, and support core security guardrails