Add FlashSprite.setOutlineByBossPhase with light/dark green shade option and red fallback; BossPhaseSystem drives HeroViewComp.applyBossPhaseOutline directly after phase switch (MON faction, no hero-level event semantics, pool-node safe); extract getFlashSprite/applyOutlineByLevel to dedupe the three outline call sites.
Add FlashSprite.setPhaseOutline (P1 default / P2 green / P3 red) and drive it from BossPhaseSystem.onPhaseEnter; reset outline on pooled boss reuse so stale tint never leaks to the next owner. Red outline material asset must be created in editor (copy green, tint red) and bound to FlashSprite.outlineMatRed.
