How to Migrate from Akaunting 2.x to 3.x with Existing Data?

Hello,

We are trying to upgrade our Akaunting installation from version 2.x (running on PHP 7.4) to version 3.x (which requires PHP 8.1+), but we're encountering multiple issues during the process.

We understand that there is no official step-by-step guide for this upgrade, and the migration seems to fail both via CLI and via the web interface, even when we carefully follow common Laravel upgrade practices.

## Our scenario:
- Original installation: Akaunting 2.1.x on PHP 7.4
- Target: Akaunting 3.0.x on PHP 8.2
- We already updated PHP and created a parallel environment.
- The `.env` file is properly configured.
- We are reusing the original database.
- `php artisan migrate` fails due to duplicate columns or existing tables.
- Running `update:all` or via `/install/updates/run/core/` throws 500 errors.
- We tried clearing cache, adjusting permissions, and analyzing Laravel logs.

## Questions:
1. Is there any **official or community-backed migration procedure** for moving from Akaunting 2.x to 3.x without data loss?
2. Are we required to perform an intermediate step or convert data manually before upgrading?
3. What are the **recommended practices for handling existing databases** when structure changes are introduced in newer versions?

We are willing to contribute back a documented guide if we can get through this successfully.

Thank you for any guidance!