v1.2.1 - Initial Export + URL Normalization

Bugfixes
• Existing notes are now exported when Desktop Integration is enabled
• Markdown files now correctly land in /notes-md/ folder
• Simplified server config: Enter only base URL (e.g. http://server:8080/)
• App automatically creates /notes/ and /notes-md/
• Both URL variants work: with and without /notes

Improvements
• Example URL now shows /notes instead of /webdav
• Progress dialog during export