Model has no knowledge about card upgrades

[Gennadiyev]

When upgrading cards in-game, the model will never know anything about the upgraded version before actually upgrading it.

[judgeou]

that's important

[CompleteDotTech]

Coverage note from the current submitted PR set: this is addressed by #85 and strengthened by #84.

#85 adds card upgrade metadata and upgrade previews to visible card payloads and glossary card entries, including is_upgradable, upgrade levels, preview cost/star cost, and preview description.

#84 adds search_wiki(), which returns profile-discovered card wiki entries with both base and upgraded variants when the card can be upgraded.

I would keep this open until the PRs are merged and verified in-game.