Feat:Enable Ask Your Corpus for document-based Q&A with RAG

Description:

This MR implements the "Ask Your Corpus" (RAG) feature, enabling users to interact with their document contributions using advanced AI. This includes a complete Retrieval-Augmented Generation pipeline integrated into the "Tools" workspace.

Key Features:

• Multi-Provider Integration: Support for OpenAI, Gemini, Groq, Qwen, and DeepSeek with automated model discovery and token budget management.
• Intelligent Indexing: Automatically generates metadata summaries, key concepts, and themes from document text using LLMs.
• Knowledge Graph: Extracts and visualizes an interactive knowledge map of entities and their relationships within the document.
• Contextual Chat: A robust query interface that provides precise answers with direct source citations and page-number references.
• Secure Credentials: Implements session-based API key management that clears sensitive data on logout or when leaving the workspace.
• Refined UI: Modern, responsive workspace design following the project's aesthetic, with loading states for indexing and interactive follow-up suggestions.

Type of Change:

• Bug Fix
• Feature Development
• Documentation

Testing:

• Tested on desktop
• Tested on mobile
• Tested in different browsers

Screenshots (if applicable):

Mobile view

Video Demo

Add a link to the demo of the PR

Checklist:

• Code follows project style guidelines
• Self-review completed
• No console errors
• TypeScript types are correct