Re-add Spring.AddTeamResourceStats for Lua economy controllers

[keithharvey]

Ported from the eco branch. BAR's resource transfer controller moves shared pools via Spring.SetTeamResource on the gadget:ResourceExcess path; without this, sharing is miscounted as production/usage. Records sent/received/excess into team + lifetime stats without moving resources.

[keithharvey]

@sprunk I did rebase master since we were pretty far behind.

[sprunk]

I think this should be just for the excess stat, since the others already have functions to adjust them.

[keithharvey]

@sprunk
So ShareTeamResource can't represent that (unless there's another call that I am missing).

1. it is 1:1 so every call forces sent==received, so it can't faithfully carry taxed sent/received. The tax that gets destroyed has nowhere to go.
2. Pooled, not pairwise - the solver gives net per-team flows, no sender -> receiver pairs. Pairs would have to be synthesized (doable but only matters if we go this way).

Poking around for another way to do this now but yeah, that's one of the main reasons I moved away from the existing API originally, it just wasn't designed with the game doing the underlying math comprehensively in mind.

That said, there is a path that uses only existing calls if we accept lossy stats under tax:

1. ShareTeamResource(sender -> receiver, net) - moves the net amount and records sent/received (both = net), after synthesizing pairs as in (2) above.
2. SetTeamResource(sender, target) - drops the destroyed tax as a pure pool reduction (SetTeamResource touches no stats, so it doesn't pollute produced/used).
3. AddTeamResourceStats(excess) - records waste only.

The catch is that ShareTeamResource being 1:1 makes sent the net delivered amount rather than the gross, and the taxed portion is destroyed silently - which is how it works today anyway, tax never lands in excess.

So the two viable options are: keep AddTeamResourceStats carrying gross sent/received/excess (faithful to the numbers the game computes), or take the ShareTeamResource + SetTeamResource route and accept sent==net under tax. I lean toward the former since it preserves the gross figures, but I'm happy either way.

[sprunk]

Stats can be implemented in Lua, and for BAR specifically there are motions in that direction already (cf. beyond-all-reason/Beyond-All-Reason#7584, beyond-all-reason/Beyond-All-Reason#6862 and the others linked from discussion there). If you go this route you can design the stats to be whatever you want.

The engine's native stats implementation seems to be designed as a sort of ledger where every resource is accounted for, with spSetTeamResource (the one call that currently breaks this invariant) being meant to be used largely as initialisation. I think it's good to keep it that way, since it's elegant in simplicity and anybody unhappy with it can use Lua. The new gadget:ResourceExcess also breaks this invariant, which is why adding a callout to control it would be alright.

[keithharvey]

Aite the consumer side wasn't as bad as I imagined because of the way stats already worked over there. I was worried I'd have to unpack waterfill into a per-team munge step and that's a hot path, but it turned out to be like 4 lines of code so yay.

Note I renamed it to AddTeamResourceExcessStats to reflect its diminished scope.

@sprunk how do you want to do this? I'm currently targetting your branch with this PR but can open a new PR and switch it to master if that's easier. Merging this should make your PR the clean merge point.

[sprunk]

I don't mind this going either onto the ResourceExcess branch or directly to master, but either way it probably shouldn't have 264 commits though. The code itself looks alright.

[keithharvey]

The 264 commits are a byproduct of the merge target being your branch, which is not rebased on master. Rebasing your branch then merging it should produce the desired single-commit merge. Or just force-pushing your branch here and merging master. I can rebase again whenever you're ready if that helps.

[sprunk]

Looks good, just minor nits.

[sprunk]

Cool, thanks.