minor: yugioh support added

docs/adding-a-new-game.md

@@ -37,6 +37,9 @@ A few traps to plan around now, before you write code:
 - **Lookup precision.** Some APIs return many ambiguous matches when you query by name only and require the set id (and sometimes the collector number) to disambiguate. Decide up front which fields make a search reliable enough to take the first result.
 - **URL encoding.** All query strings must be RFC 3986 percent-encoded before they reach `IHttpClient::get` (`cpr::Url` does **not** re-encode). The Magic/Pokemon implementations have a private `urlEncode` helper you can copy.
 - **Collector-number normalization.** Pokemon stores `4/102` but the API only accepts `4`. Whichever convention your domain type uses, normalize it inside `buildSearchUrl` so the wire format is whatever the API actually expects. Mismatches here produce empty result sets, which then look identical to "no preview available" and are very tedious to debug.
+- **Name-matching strictness.** Some APIs reject strict exact-name parameters for real-world card spelling variants (e.g. hyphenation/punctuation differences). If your provider supports fuzzy-name search, prefer that for the first request, then disambiguate in `parseResponse` using set/print metadata.
+- **400 fallback strategy.** If adding optional set filters can produce request validation errors (`HTTP 400`), add a second request path that retries without the risky filter and keeps disambiguation local in `parseResponse`.
+- **Image variant priority.** If the provider returns both cropped art and full-card images, prefer the full-card URL for selected-card preview. Use cropped variants only as fallback.
 
 ### 1.3 Flag icons
 
@@ -138,6 +141,8 @@ Mirror `core/include/ccm/games/pokemon/PokemonCardPreviewSource.hpp`. The header
 - `static std::string buildSearchUrl(std::string_view name, std::string_view setId, std::string_view setNo);`
 - `static Result<std::string> parseResponse(const std::string& body);`
 
+If your game benefits from edit-dialog metadata helpers (for example auto-detecting collector number / rarity), you can opt in to `ICardPreviewSource::detectFirstPrint(...)` and route it via `CardPreviewService::detectFirstPrint(...)`. If you need to enumerate multiple upstream printings (for example Yu-Gi-Oh! “Next” cycling between alternate `set_code` or `set_rarity` values), also override `ICardPreviewSource::detectPrintVariants(...)` and expose it through `CardPreviewService::detectPrintVariants(...)`. Keep both optional per game — default behavior should remain an explicit unsupported error.
+
 Both `buildSearchUrl` and `parseResponse` are static and pure on purpose: every URL-encoding and JSON-shape rule is testable without HTTP. Common edge cases your tests must cover:
 
 - Names with spaces, punctuation, or non-ASCII characters (percent-encoding correctness).
@@ -328,6 +333,10 @@ In the constructor:
 
 The reference implementation is `ui_wx/src/PokemonCardEditDialog.cpp`.
 
+When an extra field is from a controlled vocabulary (rarity tiers, print types, etc.), prefer a dropdown (`wxChoice`) over free text to keep list/filter values consistent and reduce user-input variants.
+
+If the external API expects a full print code (e.g. `LOB-001`) but users mostly edit only the numeric suffix, expose a numeric input plus a read-only derived preview (for example `(LOB-001)`) and compose/decompose the stored full value in `readExtraFromCard()` / `writeExtraToCard()`.
+
 ### 5.6 `<Name>GameView`
 
 This is the polymorphic glue between the new game's panels and the rest of the app. Create:
@@ -452,6 +461,8 @@ Run, in order, from the workspace root. Do not skip any step.
 These do not match a single seam in this guide but are worth calling out explicitly.
 
 - **Stale set caches.** Each `IGameView` caches `std::vector<Set> setsCache_`. After `onUpdateSets` succeeds, refresh the cache (assign the new vector). The reference implementations do this.
+- **Set ordering drift.** Keep set lists sorted by release date not only in `<Name>SetSource::parseResponse`, but also at UI consumption points (preloaded/cached vectors passed to `BaseCardEditDialog`). Older on-disk cache data or future parser changes can otherwise surface unsorted set pickers.
+- **Auto-detect feature scope.** Treat print auto-detect as a per-game capability. Do not assume every game supports it; gate UI affordances behind game-specific dialog logic and source opt-in.
 - **`signed_` / `signed`.** The C++ field is `signed_`; the JSON key is `"signed"`. This is intentional and must not be changed. The same convention applies to any new field where the natural name collides with a C++ keyword — pick a trailing-underscore C++ name and an unaliased JSON key.
 - **Spacer column index.** `BaseCardListPanel` reserves index `0` for a hidden zero-width spacer column (MSW comctl32 image-list gutter workaround). Real columns start at index `1`. If you ever need to call into `wxListCtrl` directly from a derived panel (you should not), remember this.
 - **Preview-fetch threading.** The async preview fetch in `BaseSelectedCardPanel` uses a `shared_ptr<State>` + `std::atomic alive` + `std::atomic currentGen` triple. Do not capture `this` raw in any background work you add to a new game's selected panel; copy that pattern verbatim.