Proposed License Change — Switch Satiscode from MIT to GPLv3

## **Summary**
I am proposing to relicense Satiscode from **MIT** to **GNU GPLv3**.
This change would apply to the entire project and all future contributions.

The goal is to ensure that Satiscode remains free, open, and protected from proprietary forks while still allowing use of MIT and Apache‑2.0 libraries, which are compatible with GPLv3.

I am opening this issue so contributors are aware of the change **before** it is applied.

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## **Why GPLv3?**
- Prevents proprietary or closed‑source forks
- Ensures all modified versions remain open-source
- Requires redistributed binaries to include source
- Provides strong legal protection if license violations occur
- Compatible with MIT and Apache‑2.0 dependencies already used in the project

This aligns with the long‑term goal of keeping Satiscode open, transparent, and community‑driven.

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## **What will change**
If we proceed with GPLv3:

- A `COPYING` file containing the full GPLv3 license will be added
- Short GPLv3 copyright headers will be added to source files (JS, Python, C/C++)
- Documentation will be updated to reflect the new license
- CI workflows may be updated to check for license compliance
- All future contributions must be GPLv3‑compatible
- Existing MIT‑licensed code will be relicensed under GPLv3

No contributor action is required unless you have concerns.

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## **Compatibility**
GPLv3 **can** legally include code from:

- MIT‑licensed projects
- Apache‑2.0‑licensed projects

These licenses are fully compatible with GPLv3.

GPLv3 **cannot** include code from:

- GPLv2‑only projects
- AGPL projects (unless the entire project becomes AGPL)
- Proprietary libraries without explicit GPLv3 linking permission

This change will not affect current dependencies.

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## **Contributor Feedback**
If you have questions, concerns, or objections, please comment here.

I will wait for feedback before applying the license change.

Review the proposed project-wide scope and contributor feedback first. If approved, add the COPYING file, update the documentation, add GPLv3 headers to the named JavaScript, Python, C, and C++ source files, and assess the CI workflows for license compliance. Done means the license change is applied consistently and future contribution requirements are documented.

Written by the indexing model from the issue text.