Support many:many edges with data

[xixixao]

Right now many:many edges that need to store data (or additional edges) can be modeled by two 1:many edges pointing at the same table. This is good, but perhaps it has some functionality gaps. many:many edges support looking up edge presence and traversing the edge by using a combined index, but in the case of an ent defined for this purpose the developer has to do this manually.

[matthewLuo]

I need this feature. I have a chat app with a users table and spaces table. The junction table, spaceMembers, needs to have columns like role, joinedTime, etc.

One of the key value propositions of Convex Ents is ergonomic many-to-many relationships, so it seems to be a significant loss of functionality to have to define two 1:many edges.