MINOR: define Qt port scope

AGENTS.md

@@ -13,8 +13,38 @@ This repository is a Qt 6 port of KaTrain, a KataGo frontend for Go/Baduk.
 
 - Upstream KaTrain is a Python application built with Kivy.
 - Kivy does not work well on Wayland, so this project is a Qt 6 port.
+- The goal is a PySide6 frontend for KaTrain.
 - `katrain/core` is not fully UI-independent. The first major goal is to separate the actual core functionality from UI-specific concerns before or alongside the Qt UI port.
 - Preserve upstream behavior where practical, while keeping UI abstractions out of the reusable core.
+- Do not rewrite working core logic unless necessary. Keep divergence small so upstream versions can continue to be tracked.
+
+## Scope
+
+### Non-goals
+
+- Engine or model downloading.
+- KataGo contribution.
+- Mobile support.
+- Kivy compatibility in the new frontend.
+- Sabaki theme package installation.
+
+### Required Functionality
+
+- SGF loading and saving.
+- KataGo analysis.
+- Analysis graph, move tree, candidate moves, ownership display, and principal variation display.
+- Mistake coloring.
+- Play against AI.
+- Teaching and training modes.
+- Human-like AI settings.
+- Engine restart and settings.
+- Localization, where practical.
+
+## Board Themes
+
+- Support arbitrary board texture, black stone, and white stone images.
+- Allow board, black stone, and white stone components to be mixed independently.
+- Support multiple stone image variants internally.
 
 ## Environment