Teams API

Added

• TeamRelation enum (ALLY, TRUCE, NEUTRAL, ENEMY) — models the declared relationship one team holds toward another. Includes isFriendly(), isHostile(), and isMoreHostileThan(other) helpers.
• TeamsRelationService interface: optional extension service for inter-team relation management. Methods: setRelation(fromTeamId, toTeamId, relation, initiatorUUID), getRelation(fromTeamId, toTeamId) (defaults to NEUTRAL), getRelations(teamId) (returns all non-neutral relations as an unmodifiable map), clearRelations(teamId) (for use on team disband). Default methods: areAllies(teamAId, teamBId) (mutual ALLY required), areEnemies(teamAId, teamBId) (either side suffices).
• TeamRelationChangeEvent (cancellable): fired before a team's declared relation toward another changes. Exposes getTargetTeam(), getInitiatorUUID(), getOldRelation(), getNewRelation(), and setNewRelation() so listeners can override the incoming relation before it is persisted.
• TeamsAPI facade methods: getRelationService(), isRelationAvailable(), registerRelationProvider(plugin, service), registerRelationProvider(plugin, service, priority), unregisterRelationProvider(service).
• TeamsAPI.API_VERSION bumped to 1.6.0.