jules changes, upgrades and QA

This PR upgrades the mmdGenerator codebase to version 2.0.0.

Key improvements:

• Backend Performance: Refactored the database service to use a long-lived SQLite connection managed by a FastAPI lifespan handler. Added robust error handling.
• Frontend Quality: Shifted diagram exports (PNG/PDF) to the backend for better consistency. Optimized React components with memoization.
• Full QA Suite: Added backend unit tests for services/API and frontend E2E tests using Playwright.
• Release Ready: Bumped versions and tagged v2.0.0.

v1.0.1

Full Changelog: v1.0.0...v1.0.1

Release 1.0.0

Release 1.0.0

Release 0.1.2

Release 0.1.2

Release 0.1.1

Full Changelog: v0.1.0...v0.1.1

Release 0.1.0

Full Changelog: v0.0.4...v0.1.0

v0.0.4

Full Changelog: v0.0.3...v0.0.4

v0.0.3

Full Changelog: v0.0.2...v0.0.3

v0.0.2

Full Changelog: v0.0.1...v0.0.2

v0.0.1

Full Changelog: https://github.com/markusbrand/mmdGenerator/commits/v0.0.1