feat: I/O json export import with 100% coverage

- Full FEN parser tests
- Json exporter with all move types covered
- CastleKingside branch coverage

Co-Authored-By: Claude Opus 4.6

modules/api/CHANGELOG.md

@@ -16,8 +16,3 @@
 ### Features
 
 * NCS-21 Write Scripts to automate certain tasks ([#15](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/15)) ([8051871](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/80518719d536a087d339fe02530825dc07f8b388))
-##  (2026-04-07)
-
-### Features
-
-* NCS-21 Write Scripts to automate certain tasks ([#15](https://git.janis-eccarius.de/NowChess/NowChessSystems/issues/15)) ([8051871](https://git.janis-eccarius.de/NowChess/NowChessSystems/commit/80518719d536a087d339fe02530825dc07f8b388))

modules/api/versions.env

@@ -1,3 +1,3 @@
 MAJOR=0
-MINOR=3
+MINOR=2
 PATCH=0