[DeckShare] Browse and open public decks with loading, error and accessibility states

Add a public-decks tab that lists decks published by other users using the
server's deck visibility feature, previewing each deck's banner card, color
identity, tags and upload time without downloading the deck list until the
user opens it.

- Add a public-decks tab with a shared-settings widget and a remote model
  that fetches the target user's decks and refreshes both automatically and
  on user request, with a loading indicator and a server-error message
  instead of a blank tab when the fetch fails or the connection drops
- Render each deck as a focusable preview tile whose banner, color identity,
  tags and upload time follow the existing Preview settings, with the deck
  name announced as the tile's accessible name and Space/Enter opening the
  deck, mirroring the shared-deck preview tile
- Show a message box when opening a public deck fails or arrives corrupted
- Publish and unpublish decks from the server storage toolbar and context
  menu, toggling the deck's own visibility bit (what the server persists)
  rather than the inherited effective state, and batch the visibility
  refresh until the last in-flight change is acknowledged
- Add the Show Upload Time setting so the tile's upload stamp can be hidden
  like the other preview details
- Update the retranslateUi wiring for the new public-decks tab and rename
  the share action tooltip from "Deck share" to "Share link"

cockatrice/src/interface/widgets/dialogs/dlg_share_deck.cpp

@@ -72,11 +72,7 @@ void DlgShareDeck::shareFinished(const Response &response, const CommandContaine
 
     const Response_DeckShareCreate &resp = response.GetExtension(Response_DeckShareCreate::ext);
     const QString token = QString::fromStdString(resp.token());
-#if QT_VERSION >= QT_VERSION_CHECK(6, 7, 0)
     const QDateTime expiry = QDateTime::fromSecsSinceEpoch(resp.expires_at(), QTimeZone::UTC);
-#else
-    const QDateTime expiry = QDateTime::fromSecsSinceEpoch(resp.expires_at(), Qt::UTC);
-#endif
 
     const QString link = DeckShareUtils::buildShareLink(client, token);
     DeckShareUtils::copyShareLinkToClipboard(link);

cockatrice/src/interface/widgets/tabs/tab_deck_storage.cpp

@@ -795,11 +795,7 @@ void TabDeckStorage::shareFromTreeFinished(const Response &response, const Comma
     }
     const Response_DeckShareCreate &resp = response.GetExtension(Response_DeckShareCreate::ext);
     const QString token = QString::fromStdString(resp.token());
-#if QT_VERSION >= QT_VERSION_CHECK(6, 7, 0)
     const QDateTime expiry = QDateTime::fromSecsSinceEpoch(resp.expires_at(), QTimeZone::UTC);
-#else
-    const QDateTime expiry = QDateTime::fromSecsSinceEpoch(resp.expires_at(), Qt::UTC);
-#endif
 
     const QString link = DeckShareUtils::buildShareLink(client, token);
     DeckShareUtils::copyShareLinkToClipboard(link);

cockatrice/src/interface/widgets/tabs/visual_deck_storage/tab_deck_storage_visual.cpp

@@ -169,11 +169,7 @@ void TabDeckStorageVisual::shareFinished(const Response &response, const Command
 
     const Response_DeckShareCreate &resp = response.GetExtension(Response_DeckShareCreate::ext);
     const QString token = QString::fromStdString(resp.token());
-#if QT_VERSION >= QT_VERSION_CHECK(6, 7, 0)
     const QDateTime expiry = QDateTime::fromSecsSinceEpoch(resp.expires_at(), QTimeZone::UTC);
-#else
-    const QDateTime expiry = QDateTime::fromSecsSinceEpoch(resp.expires_at(), Qt::UTC);
-#endif
 
     const QString link = DeckShareUtils::buildShareLink(tabSupervisor->getClient(), token);
     DeckShareUtils::copyShareLinkToClipboard(link);