A8: Extract scoring module #128

Summary

Extract kill tracking, damage ledger, frag/score/time limit checking, and end/restart game logic into a standalone scoring module DLL.

Responsibility

• Kill attribution (track who killed whom and how)
• Score tracking (kills, deaths, points per player)
• Damage ledger (last-hit attribution for indirect kills)
• Frag limit checking
• Time limit checking
• End game condition detection and notification
• Restart game flow
• SCORE_CHANGE_MESSAGE and SCORE_MESSAGE wire construction
• Fire events: score_changed, game_ended, game_restarted

Acceptance Criteria

• Scoring tests pass through module interface
• Frag limit and time limit triggers work
• End/restart game flow matches current behavior
• Configurable via TOML (kill_points, death_penalty, team_kill_penalty)

Depends on: #125, #127 (combat module fires ship_killed)
Blocks: #120