feat: track death handicap per island instead of per world

[tastybento]

Problem

Level read death counts from BentoBox core's per-player, per-world counter (Players.deaths) at calculation time. Now that players can have multiple islands and join teams while keeping their own islands, this caused:

• A player joining a team immediately raised the team island's death handicap with their entire world death history (core's team-join-reset only fires when the joiner's own islands are deleted on join, i.e. when disallowTeamMemberIslands is true).
• reset-on-new-island zeroed the whole world count, wiping the deaths that were effectively counting against the player's other islands in that world.
• All of a player's islands in a world shared one death count, and deaths anywhere in the world counted — even while visiting someone else's island.

Reported on Discord by mrFloris/chunkblock.

Solution

Level now tracks deaths itself, per island, stored in IslandLevels:

• A death only counts if it happens in the island space of an island the dying player is a member of. Deaths in other worlds or on other people's islands are ignored. Core's deaths.counted and deaths.max game mode settings are honoured.
• Per-player counts are kept so the admin level report can show who died; each is capped at the game mode's deaths.max.
• When a member leaves or is kicked, their balance is folded into a per-island anonymous death count — an island's handicap never decreases just because an often-dying member left. Leave-and-rejoin does not double count.
• Island reset/deletion clears the island's death data, giving per-island reset-on-new-island semantics with no config needed.
• Team join carries nothing over, regardless of core settings.

Migration

Legacy per-world counts are migrated once per island, on first touch (calculation, death, or member departure — whichever comes first). The seed reproduces exactly what the old formula would compute at that moment (sum of member deaths if sumteamdeaths, else owner deaths) and is stored as anonymous deaths, so island levels do not change on upgrade.

sumteamdeaths is deprecated and only read for the migration seed; the new model always counts all deaths that occurred on the island.

Notes for admins

• Core's /[admin] deaths set|add|reset commands and the team-join-reset / reset-on-new-island settings no longer influence island levels (core's counter is untouched and still drives core placeholders).
• The level report now breaks the handicap down per member by name, with a labelled line for former-member/migrated deaths.

Tests

New coverage for: migration seeding in both sumteamdeaths modes (and no re-seed on second call), death cap and deaths.max: 0, member/non-member/off-island/non-game-world deaths, leave/kick rollover preserving the island total, and the handicap reducing the level in tidyUp(). Full suite: 256 tests, all passing.

🤖 Generated with Claude Code

https://claude.ai/code/session_01NSvRYW3Rgh6Vgvx62QRYE1

[sonarqubecloud]

Quality Gate passed

Issues
1 New issue
0 Accepted issues

Measures
0 Security Hotspots
89.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud