Rejoin detection: link reconnecting player to existing session

Description

If a player disconnects mid-race (crash, network drop) and rejoins within a grace period, they should be re-linked to their existing ECS entity with their score and ring progress intact — not start fresh or be blocked from rejoining.

Acceptance Criteria

• On player join: check if an active SessionComponent exists for that UUID in the current game instance
• If found and race is still active: restore player to their entity, respawn at last known position, restore HUD state
• Grace period: 60 seconds (configurable in map config) before the slot is freed
• If grace period has expired: player joins as spectator or new lobby participant
• If no active session: normal first-join flow
• Unit test covers: disconnect during game → rejoin within grace period → state restored correctly

Technical Details

• SessionComponent must store last-known position and disconnect timestamp
• Rejoin logic hooks into the Minestom player-join event handler in server
• Must not conflict with PlayerPhaseSystem creating a duplicate entity

Dependencies

• "Persist player profiles on first join" should be done first

Estimate

M

Start in the server's Minestom player-join event handler and inspect SessionComponent and PlayerPhaseSystem to understand the existing join and entity-creation flow. Confirm that persisted player profiles are available first, then implement the rejoin path with configurable grace-period state. Done means rejoining restores the existing entity, position, score, ring progress, and HUD without duplication, with a unit test covering disconnect and rejoin.