Reimplement native market pricing and goods trading

[Krarilotus]

TL;DR: Reimplements the game's market prices and AI goods trading, preserving how purchases and sales change stored resources and gold. Adds a short wiki description of these rules.

The four C++03 implementations use the existing types and resolvers:

Function	Original address	Raw reccmp score
GameStateStructures::getBuyPrice	0x004588A0	100%
GameStateStructures::getSellPrice	0x00458910	100%
AICState::buyGoods	0x004CC000	85.71%
AICState::sellGoods	0x004CBFA0	81.82%

Prices preserve division before multiplication. Purchases charge gold only after resource storage succeeds; sales preserve the order of gold/statistics updates, resource removal and trade display. Field access uses the struct resolver's instance; member-call arguments use ptr.

Rebuilt the full OpenSHC.dll with MSVC 2005 SP1 x86, CMake 3.31.6 and RelWithDebInfo, selecting these four sources locally. Compared each function against Crusader 1.41 SHA256 3bb0a8c1e72331b3a30a5aa93ed94beca0081b476b04c1960e26d5b45387ac5a. The trade diffs are confined to resolver calls and symbolic global references; control flow, register use and field accesses match. The soft status entries use 100.0% following the review guidance for these resolver-only differences; the table above retains the raw scores.

The comparison build uses a current Windows SDK manifest tool because the legacy mt.exe crashes on this machine. Compiler and optimization settings remain the project's; no build override is included in the PR. The DLL has not been deployed or tested in-game.

Overlap: origin/reimpl/simple-functions-set-1 at 5b9da3d already contains the two price implementations, with identical expressions. The AI trade routines are additional. These price files can be dropped when that branch lands; no competing implementation is intended.

[TheRedDaemon]

Hi, thanks for the contribution!

Comments are on the code, also:

We have a "soft" status file status/addresses-SHC-3BB0A8C1.txt where we track the general status of the functions to avoid heavier test pipelines for the start.

The structure should be self explaining, just check some entries by searching for Reimplemented. The percentage also does not have to be too precise. If the only mismatches are the resolvers/proxies and the structure fits, saying "100.0%" is ok. If the structure still has issues, the percentage (with struct resolvers active) is ok.

Now I will also mention @gynt and add him to the review, since I will give him the final word on the wiki entry/purpose. Also, he has a lot of smaller functions in his branches and needs to check if they overlap with your MR.

[TheRedDaemon]

Did you replace something here?

[Krarilotus]

No existing entry was replaced: the diff adds only the market-trading link below the load-balancing page. The rest of the index is unchanged.

[gynt]

I think it is unclear that this article will be about AI. Please add a AI subsection and add this entry to it with AI in the title. And make sure the .md file refers to AI market behavior explicitly.

[Krarilotus]

Updated in 9edc084: field access now uses instance, the redundant comments are removed, and the wiki describes vanilla trading behavior without build-process details. I also added the four soft status entries. Fresh RelWithDebInfo DLL comparisons give 100% for both price functions; the trade routines retain the resolver-only differences documented in the PR, so their status follows the suggested 100.0% convention.

I checked Gynt's reimpl/simple-functions-set-1 branch as well: it already has both price expressions. The AI buy/sell routines are additional; I have noted the overlap in the description so the price files can be dropped when that branch lands.

[gynt]

I think it is unclear that this article will be about AI. Please add a AI subsection and add this entry to it with AI in the title. And make sure the .md file refers to AI market behavior explicitly.

[TheRedDaemon]

Looks good from my side.