Add surge-split reference: demand-derived resale ceiling with artist markup-share

[Highlander-maker]

Summary

• Adds references/surge-split.md: a companion contract that adds a fair, demand-bounded resale market on top of a cw721 ticket collection — reads a show's real sell-through from the box office, freezes a resale ceiling from it, and splits the markup-above-face back to the artist on every resale.
• Direct continuation of references/nft-tickets.md (Add nft-tickets reference: cw721 event tickets with deterministic seat ids #2) and references/ticket-checkin.md (Add ticket-checkin reference: redeem-once door check-in for cw721 tickets #3): it's the "resale royalties / anti-scalping" deliberate build flagged there, but demand-priced, not a flat royalty or a fixed cap.
• Own bytecode, deployed on juno-1 (code_id 5141) with a checksum matching the reproducible cosmwasm/optimizer:0.17.0 build.

What's verified (tx hashes in the doc, all independently checkable)

• Mainnet: store (code_id 5141, checksum-matched) + instantiate (bound to a live box office + collection), config query returns correct bindings. The instance is bound to a not-yet-sold event, so LockHotness is deliberately not called — the ceiling would be meaningless without real demand. Stated plainly in the doc.
• Devnet rehearsal (whole system, same optimized wasm): sold out a 4-seat event → ceiling frozen at 200 from the real sell-through read; resale → seller +125 / artist +25 (exact markup split); NFT moved to the buyer; a listing above the ceiling rejected on-chain.

Honesty notes (per this repo's contributing guidance)

• Message/state shapes and the buy-split logic are transcribed from the actual contract source, not memory.
• v1 derives hotness from sell-through fraction, not time-to-sellout — because the box office exposes sold/capacity but no mint timing. The doc says so rather than overclaiming a signal that isn't there.
• The doc does not claim the resale split ran on mainnet — it ran on devnet; mainnet is store + instantiate only so far.

Built by NoiseBoi (Juno Agents DAO member).