feat(chatbot): Add AI ChatBot module with backend services, frontend drawer component, and E2E tests

[sugrivapardhavaajith-alt]

📌 Summary
This PR introduces the AI ChatBot feature to the platform. It integrates a dedicated chatbot backend module, a Python AI engine service, an interactive frontend UI component (ChatbotDrawer), and end-to-end automated tests.

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🚀 Key Changes

⚙️ Backend & Infrastructure

• ChatBot Module (backend/src/modules/chatbot/):
  • Implemented ChatbotController for handling API requests/responses.
  • Implemented ChatbotService and input validation (ChatbotValidators).
  • Added module container configuration and main exports.
• Python AI Engine (backend/src/modules/chatbot/python/):
  • Integrated chatbot_service.py & main.py for handling AI processing.
• Database & Auth Support:
  • Enhanced MongoDB provider and User Repository (MongoDatabase.ts, UserRepository.ts).
  • Adjusted BaseService, AI config, and Firebase Auth handling.
• Dev Utilities:
  • Added backend/scripts/dev-with-memory-db.js for standalone development and testing.

🎨 Frontend & UI

• ChatBot Interface (frontend/src/components/chatbot/ChatbotDrawer.tsx):
  • Built an interactive drawer interface for conversing with the AI assistant.
• Navigation Integration (StudentSidebar.tsx):
  • Integrated the ChatBot launcher directly into the student navigation sidebar.
• API Client & Firebase (api-client.ts, firebase.ts):
  • Configured client-side API routing and authentication header support for ChatBot endpoints.

🧪 Testing

• E2E Test Suite (e2e/tests/chatbot.spec.ts):
  • Added Playwright automated tests to verify ChatBot UI interactions, message sending, and response rendering.

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🔍 How to Test

1. Backend: Run pnpm --filter backend dev (or node scripts/dev-with-memory-db.js). Verify that /api/v1/chatbot endpoints respond correctly.
2. Frontend: Launch the student dashboard, open the sidebar, click on the ChatBot icon/button, and verify smooth message sending and response handling in ChatbotDrawer.
3. Automated E2E Tests: Run npx playwright test e2e/tests/chatbot.spec.ts to verify integration tests pass cleanly.

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