Refactor: Update architecture diagram with new modules and web support

This commit updates the application's architecture diagram (`NoteDelightDiagram.drawio`) and its corresponding PNG export.

The key changes include:
- Splitting the single "Shared module" into three distinct core modules: `:core:data`, `:core:domain`, and `:core:presentation`.
- Adding a "Web app" target and its corresponding `wasmJs` source set, demonstrating expanded platform support.
- Reorganizing and repositioning elements for better clarity and to reflect the new modular structure.

Author: softartdev