feat(seller): restock sold out items in batches instead of one stack per cycle

[icemansparks]

Problem

When an item sells out (Thick Leather was the reported case) it takes a long time to come back, and then only one stack at a time.

GetItemsToSell() builds its priority block by walking itemPriceOverrides and pushing each item that is not currently in the auction house once. With ~11.5k price override rows, a specific missing item has to win a shuffle against every other missing item to land inside that cycle's ItemsPerCycle (200) budget — hence the wait. And because itemsInAH is snapshotted at cycle start and the item appears once, it can only ever be relisted as a single stack per cycle.

Change

The priority block now queues an item as many times as it is short of its target count:

• target = mod_auctionhousebot_countOverride.targetCount, else the global AuctionHouseBot.DuplicatesCount, else 1 — the same precedence the per-listing cap in Sell() already applies, so the batch can never overshoot (botItemCounts is incremented per listing).
• sold out items first, then items still partially stocked (top-up), each group shuffled independently.
• copies are expanded after the shuffle so they stay adjacent — an item that gets picked gets its whole batch, rather than the batch being split across cycles.

New setting AuctionHouseBot.RestockBatchSize (default 5) bounds how many stacks of one item a single cycle may queue, so one item with a target of 50 cannot eat the whole ItemsPerCycle budget. Set it to 1 for the previous one-stack-per-cycle behaviour.

TraceSeller now logs how many items were sold out vs understocked per cycle.

Behaviour notes

• With ~10.6k countOverride rows loaded, the priority block is now larger and blocks 2–4 (random duplicates / non-override bins) are reached even less often than before. That is intended: restocking is now targeted instead of random.
• Existing setups with no countOverride rows and DuplicatesCount = 0 see no change (target falls back to 1 stack).
• Cost is unchanged in order of magnitude — blocks 3 and 4 already pushed the full item bins each cycle.

Verification

• Restock math checked against a standalone harness mirroring missingStacks() (sold out / partial / at target / no override / batch size 1 / batch size 0) — all assertions pass.
• Full module compile: the core-build workflow on this PR.
• Not yet built or run on testcore (LXC 113).

Files

• src/AuctionHouseBot.cpp — batching logic in GetItemsToSell(), botItemCounts passed in
• src/AuctionHouseBot.h — signature
• src/AuctionHouseBotConfig.{h,cpp} — RestockBatchSize
• conf/mod_ahbot.conf.dist — setting + docs