• Attempts to improve an item via a Skill Development Roll (SDR): rolls 1d100 + {@link SdrImprovable.sdrSkillBase} against the current base mastery level, and on a success raises the persisted masteryLevelBase by SdrImprovable.sdrIncr. The outcome is persisted — the improve flag is cleared either way and, on success, the raised base mastery level is written back — and then posted to chat.

    The shared executor body behind every kind's improveWithSDR action. The write targets this item alone, so improving a Mystical Ability can never alter the Skill it is associated with.

    Parameters

    Returns Promise<void>

    Resolves once the roll is evaluated, persisted, and the chat card is posted.