Feature: Session history recovery API + localStorage persistence

[anushagarg6]

Description

The backend Redis session store survives server restarts and correctly stores conversation history per session. However there is no GET /api/session/<id> endpoint to retrieve this history, and the frontend stores all conversation data in a volatile in-memory object (const conversationStore = {} in chat.js).

Impact

Refreshing the browser wipes all chat history from the UI even though the data is still in Redis. Users cannot resume previous conversations after a page reload.

What Needs to Be Built

Backend (backend/app.py)

Add a new route:

@app.get("/api/session/{session_id}")
def get_session(session_id: str):
    history = get_history(session_id)
    return {"session_id": session_id, "history": history}

Frontend (frontend/js/chat.js)

• Persist active sessionId to localStorage on first message
• On page load, check localStorage for a saved session ID
• If found, call GET /api/session/<id> to restore messages into the UI

Files Affected

• backend/app.py
• backend/sessions.py
• frontend/js/chat.js