GameSim snapshots the state before each undoable command
(PlacePiece / RemovePiece / MovePiece) into a bounded LinkedList stack
(max 32). Undo() pops the last checkpoint and emits StateRestoredEvent,
reusing the presentation rebuild path already wired for QuickLoad.
Ctrl+Z in Main triggers the engine method; the harness exposes undo()
for tests. QuickLoad clears the stack (fresh timeline). Seven unit tests
cover empty stack, place/remove/move undo, reverse-order multiple undos,
rejected commands not checkpointing, and post-simulation rewind.
BoardState.CaptureSave/RestoreFromSave deep-copy every mutable field
(grid, pieces, demands, transformers, buffers, stock, campaign progress)
into a WorldSave slot. GameSim.QuickSave/QuickLoad expose slotted saves
and emit StateSavedEvent / StateRestoredEvent — the latter carries a
fresh BoardSnapshot so the presentation can rebuild board, pieces,
trajectories, objectives, stock, camera, and control bar in one pass.
F5/F9 trigger it in Main; harness gains quick_save/quick_load commands so
UI tests can checkpoint a scenario and resume without replaying from
scratch. Seven xUnit tests cover the roundtrip (including independence
from post-save mutations, campaign state, and multi-slot isolation).
Bundles in-flight work on the campaign/missions system (CampaignDef,
MissionDef, TerrainPatch, TransformerDef, MissionChecker, CampaignLoader,
FlavorBanner, transformer rules), plan files, and matching tests. Baseline
commit so the upcoming automation testing harness lands on a clean tree.
Black box sim engine (commands in, events out) with 3 piece types
(Rook, Bishop, Knight), cargo transfer system with social status
priority, collision detection, and victory/defeat conditions.
57 tests covering rules, simulation, loading, and solvability.
Godot 4 presentation layer scaffolding.
