Register the Steam app at \$9.99 and set up premium scenario-pack DLC

[charneykaye]

Register the base app and DLC in Steamworks for the paid model.

The repo now documents a $9.99 base app + premium scenario-pack DLC model, but nothing is registered with Valve yet. This issue tracks the Steamworks side.

Base app

• Set the base price to $9.99 USD (a normal paid app — not Free to Play), with regional pricing per Valve's suggested tiers.
• Create a normal paid base package containing the three platform depots (do not rely on Valve's auto free-to-play package).
• Complete the IARC questionnaire with real-money purchases = Yes (base + DLC), keeping the PG–PG-13 content answers.

Premium scenario-pack DLC

• For each premium pack, register a DLC App ID + content depot associated with the base app, with its own price.
• Record the App ID ↔ pack id ↔ depot id mapping in the private repo's STEAM_DLC_REGISTRY.md.

References

• publishing/STEAM_APP_REGISTRATION.md — Pricing and DLC configuration
• publishing/STEAM_STORE_PAGE.md — pricing/DLC store copy and IARC answers
• docs/DLC_MODEL.md — the private-repo → Steam-DLC contract

Blocks the store URL (#362) and the CI ownership wiring (#363).