NEW: server/scripts/combat/lag_compensation.gd
- 128-entry ring buffer of player positions per server tick
- rewind_and_raycast(tick, origin, direction, range, exclude):
saves current positions, rewinds to tick-time positions,
performs PhysicsDirectSpaceState3D.intersect_ray(), restores
- Falls back to normal raycast if history missing for tick
- shot_processed signal
NEW: scripts/combat/damage_processor.gd
- Processes WeaponServer hit results: applies damage, tracks kills
- Optional distance-based damage falloff
- player_damaged / player_killed signals
- Health and kill-count queries
MODIFY: server/scripts/weapons/weapon_server.gd
- fire() now takes tick parameter: fire(tick, player_id, ...)
- _perform_hitscan() uses LagCompensation.rewind_and_raycast()
when lag_compensation reference is set and tick >= 0
- Non-compensated fallback path preserved
MODIFY: server/scripts/game_server.gd
- Adds _current_tick counter, incremented each simulation tick
- Creates WeaponServer + LagCompensation + DamageProcessor as children
- record_tick() called before each tick's simulation
- register/unregister_player_node() for player lifecycle
- _on_player_killed() relays kill events via player_damaged signal
MODIFY: scripts/network/server_main.gd
- _spawn_player() registers node with GameServer.register_player_node()
- _despawn_player() unregisters via unregister_player_node()
