[Client] Show localized card names, texts and pictures

Localization wiring now runs end to end: the oracle importer collects
foreignData for the configured language and the client renders it.

- [Oracle] Import localized names and rules texts for the selected cardLang
  - single-face cards store their foreignData name and full text
  - multi-face (split/adventure/aftermath/prepare) cards collect the joined
    name once and join each face's translated text with the same separator
    as the English merge; an incomplete translation falls back to English;
    the joined text follows the same highest-priority-set policy as the
    single-face path and is only collected when localization is enabled
  - the wizard switching languages re-imports the card database

- [Client] Display localized card info throughout the client
  - card info text/picture widgets and the game board re-render on language
    change
  - pictures resolve cardLang art through Scryfall's named endpoint using the
    localized name, falling back to id-based art when no match exists
  - deck editor keeps canonical English names as card identity (EditRole)
    while showing localized names (DisplayRole), so decks and wire names
    stay stable

- [Card] Add CardLocalization-backed name/text lookup and cards.xml v4
  localization elements with a bounded-size translation cache

- [Tests] Cover oracle foreignData import (incl. multi-face joins, priority
  and fallback paths), XML v4 localization parsing, deck model localized
  display and the language-aware settings default

Existing installations need to re-run Oracle to see translations: localized
data only lands in cards.xml when the Oracle app is started with the
preferred language selected — launch the separate "Oracle" program that
ships with Cockatrice, pick the language in the wizard and let it re-import
the card database.

The client's database cache (cards.xml.cache) is invalidated by the cache
format bump and the source-hash checks, but a cache written before the
re-import can still hold English-only entries (the hash uses file size and
mtime, so a same-size/same-timestamp rewrite may be served as-is); delete
cards.xml.cache and relaunch if no localized names/texts show up after
re-importing.

oracle/src/oracleimporter.h

@@ -107,7 +107,8 @@ public:
     SplitCardPart(const QString &_name,
                   const QString &_text,
                   const QHash<QString, QString> &_properties,
-                  const PrintingInfo &_printingInfo);
+                  const PrintingInfo &_printingInfo,
+                  const QString &_localizedText = QString());
     inline const QString &getName() const
     {
         return name;
@@ -116,6 +117,13 @@ public:
     {
         return text;
     }
+    /**
+     * @brief The cardLang rules text of this face's foreignData entry, if any.
+     */
+    inline const QString &getLocalizedText() const
+    {
+        return localizedText;
+    }
     inline const QHash<QString, QString> &getProperties() const
     {
         return properties;
@@ -128,10 +136,18 @@ public:
 private:
     QString name;
     QString text;
+    QString localizedText;
     QHash<QString, QString> properties;
     PrintingInfo printingInfo;
 };
 
+struct LocalizedCardEntry
+{
+    QString name;
+    QString text;
+    CardSet::Priority priority = CardSet::PriorityLowest;
+};
+
 class OracleImporter : public QObject
 {
     Q_OBJECT
@@ -171,12 +187,53 @@ private:
      */
     QAtomicInt importCancelled;
 
+    /**
+     * The ISO-639 language code whose foreignData is imported; "en" by default.
+     */
+    QString cardLang = "en";
+
+    /**
+     * Whether cardLang is a supported language other than English, so per-card
+     * foreignData scanning can be skipped entirely when disabled.
+     */
+    bool localizationEnabled = false;
+
+    /**
+     * Localized name/text collected per imported card key while parsing sets,
+     * applied to the CardInfo objects by applyLocalizedData() once all
+     * printings have been seen so the best-priority one wins.
+     */
+    QMap<QString, LocalizedCardEntry> localizedEntries;
+
+    /**
+     * cardLang rules text collected for split-card names while parsing sets,
+     * applied by applyLocalizedData(). Kept apart from localizedEntries because
+     * MTGJSON emits each split face as its own card object with the joined name
+     * on every foreignData entry: names and the per-face text join have different
+     * completeness and must not overwrite each other under the same key.
+     */
+    QMap<QString, LocalizedCardEntry> splitLocalizedTexts;
+
     CardInfoPtr addCard(QString name,
                         const QString &text,
                         bool isToken,
                         QHash<QString, QString> properties,
                         const QList<CardRelation *> &relatedCards,
                         const PrintingInfo &printingInfo);
+
+    /**
+     * Records the first foreignData entry matching cardLang for the given card
+     * key, keeping the entry from the highest-priority set seen so far.
+     *
+     * Multi-face cards (split, adventure, aftermath, prepare) pass collectText =
+     * false: MTGJSON emits one foreignData entry per face with the same joined
+     * name but only that face's text, so the name is collected here while the
+     * per-face texts are joined during the split-card merge.
+     */
+    void collectForeignData(const QString &cardKey,
+                            const CardSetPtr &currentSet,
+                            const QJsonObject &card,
+                            bool collectText = true);
 signals:
     void setIndexChanged(int cardsImported, int setIndex, const QString &setName);
     void dataReadProgress(int bytesRead, int totalBytes);
@@ -195,6 +252,15 @@ public:
     {
         progressReporting = enabled;
     }
+    /**
+     * Selects the ISO-639 language code whose foreignData is imported.
+     * English (the default) and unsupported codes disable localization.
+     */
+    void setCardLang(const QString &lang);
+    const QString &getCardLang() const
+    {
+        return cardLang;
+    }
     /**
      * Scans the given JSON document for set metadata. Takes the data by value so
      * the wizard can hand over its decompressed buffer without copying it.
@@ -212,6 +278,12 @@ public:
     {
         importCancelled.storeRelease(1);
     }
+    /**
+     * Applies the collected localized names/texts to the imported cards.
+     * Called automatically at the end of startImport(); exposed separately so
+     * tests can drive it after importing sets directly.
+     */
+    void applyLocalizedData();
     bool saveToFile(const QString &fileName, const QString &sourceUrl, const QString &sourceVersion);
     int importCardsFromSet(const CardSetPtr &currentSet, const QJsonArray &cardsList);
     /**