Combat Auto-Save & Crash Recovery

[FirebrickRed]

Summary

Persist active combat sessions to YAML so they survive server crashes/restarts. Save on each turn change, restore on server startup.

Phase: Post-MVP Combat Enhancement
Systems: Combat System, Persistence

Prerequisites

• Combat Session Foundation & Initiative System #97 - Combat Session Foundation (completed)
• Turn Management & Action Economy #98 - Turn Management & Action Economy

Goals

• Save combat state to YAML on each turn transition
• Restore active combat sessions on server startup
• Clean up save files when combat ends normally
• Handle offline players/entities gracefully during restoration

Save Location

plugins/jkvttplugin/CombatSessions/<session_id>.yml

YAML Schema

session_id: "uuid"
dm_id: "uuid"
round_number: 3
current_turn_index: 2
is_setup_phase: false
combatants:
  - id: "player-uuid"
    type: PLAYER
    display_name: "Aragorn"
    base_name: "Aragorn"
    initiative: 18
    initiative_bonus: 3
    is_surprised: false
    is_hidden: false
    is_unconscious: false
    is_dead: false

Implementation Notes

• TurnState is NOT persisted (turn restarts fresh after crash)
• Need Combatant.fromSavedData() factory for lightweight reconstruction without live Player/Entity
• Save triggered in CombatSession.nextTurn() after advancing
• Delete save file in CombatSession.endCombat()
• Load all on plugin enable, register in static maps

Related Issues

• Combat Session Foundation & Initiative System #97 - Combat Foundation (completed)
• Turn Management & Action Economy #98 - Turn Management (prerequisite)