Remove placeholder note for screenshot in README

feat: add a guided onboarding tour for new users

feat: Refine LLM system prompt with new behavioral constraints

feat: Add Sample Strategies modal to the Navbar, enabling users to inject predefined prompts into the chat input.

feat: Filter chat messages to only include role and content for LLM API and update README styling.

feat: Refine LegalLens AI system prompt for detailed legal strategy and update README screenshot.

feat: Upgrade LLM model to gpt-4o, improve CORS origin parsing, and update README with a live demo link and screenshot path.

feat: Validate MongoDB URL format and strip quotes during parsing.

feat: Make CORS allowed origins configurable via environment variable and strip whitespace from the MongoDB URL.

build: add .python-version file specifying Python 3.11.9

refactor: Switch JWT library from `jose` to `PyJWT` and update exception handling.

add: README

feat: Add a Procfile for backend deployment and make the frontend API URL configurable via environment variables.

feat: Provide current plan context to the LLM and improve chat interface feedback for plan updates.

test: Implement comprehensive unit and integration tests for both backend and frontend components, including new pytest and vitest configurations.