Checklist

• I've searched the issues and pull requests for similar looking suggestions.
• I've checked the Unreleased section of the changelog for newly added features that sound like my suggestion.

Describe your Suggestion

For loot notifications from NPC kills, include an indicator of whether the kill was on a slayer task or not. Ideally this would show as a field on the Discord embed (e.g. "Slayer Task: Yes/No") and also be included in the webhook metadata so custom webhook servers can use it.

Reasoning

I think this would be nice so that:

• Drops can be separated into on-task vs off-task, which is useful for anyone tracking slayer progress or attributing loot to a task grind.
• Custom webhook servers could branch on it (e.g. route or tag on-task drops differently) — right now there's nothing in the loot payload that indicates task state, so it can't be derived after the fact.
• It would make slayer-focused loot logs more meaningful at a glance without having to cross-reference the separate slayer task-completion notification.