What is the complete list of possible auras that can be detected by an Aura Seer, and what causes those auras to appear?
Aura is another word for what the code internally calls "Player Modifiers", e.g. changing a player's witchcraft status.
If something can alter a player's properties, it's an aura.
Player Modifiers are also used to add any extra effects to players which may have an on daybreak/nightfall trigger - one such example would be
Poisoned. These are all classed as auras and will be visible.
I did toy with the idea of making some auras invisible at one point, although this idea never made it into the code.
This question asks what auras in werewolf override each other if, for example one gives a player a positive witchcraft status and one (such as the veil of shadows) hides that status. I will edit the answer in that question with a version of the most up to date list.