Contributor Skill Notes

Goal

Extend game modes/maps without destabilizing authoritative movement netcode.

Guardrails

1. Keep movement protocol ownership in Scripts/Net/*; do not move movement replication into RPC/MultiplayerSynchronizer.
2. Preserve 60 Hz server/client simulation and run movement simulation only in _PhysicsProcess.
3. Keep local prediction + sequence-based reconciliation intact for local player.
4. Keep remote interpolation in _Process with buffered snapshots.
5. Any new mode logic must be additive around the net layer, not inside packet codec paths.

Where To Extend

• New modes: add IGameMode implementations in Scripts/GameModes.
• New maps: replace world geometry setup in Scripts/Bootstrap/Main.cs while keeping collision semantics compatible with CharacterBody3D.
• UI: extend Scripts/UI/MainMenu.cs and Scripts/Debug/DebugOverlay.cs without changing net packet formats.

Netcode Safety Checklist

• Do sequence numbers remain monotonic and acked correctly?
• Are yaw/pitch still included in input and snapshots?
• Is correction still snap-vs-smooth threshold based?
• Are channels still separated: input CH0, snapshot CH1, control CH2?
• Is packet allocation behavior still bounded?