[Client] Expose custom zone management in the deck editor (#7205)

* [Client] Expose custom zone management in the deck editor

Wires the state layer into every editor surface that shows deck zones.

- Deck dock: context menu on zones gains New/Rename/Delete/Change
  board actions, with per-zone submenus for adding cards.
- Card database dock and visual database display gain an add-to-zone
  submenu listing custom zones per board plus a create-zone entry.
- All prompt call sites pass validateNewZoneName so duplicates and
  reserved names are rejected inline before Ok unlocks.
- Rename reuses the same dialog in name-only mode, keeping one
  validation contract for every zone-name entry point.
- Change board marks the current board instead of offering a no-op,
  and the state layer refuses moves onto boards holding a same-named
  zone from imported decks.

* [DeckEditor] Address custom-zone menu and export review feedback

* [DeckLoader] Keep the sideboard marker and block ordering when exporting nested zones

- saveToStream_DeckZone threads the owning board zone name down to the card
  writer, so cards in a custom zone under the sideboard keep their SB:
  prefix instead of being re-imported into the maindeck
- nested sub-zones are collected during the loop and written after the
  parent zone's own header and cards, so they no longer read as part of the
  zone printed before them

* [DeckEditor] Fix move-to-zone menu use-after-free and per-zone enabled state

- resolve the card name/provider/collector number before createNewCustomZone
  rebuilds the model tree, then re-find the refreshed index via findCard and
  move it (mirrors the decrementCard re-find pattern)
- the enabled test now compares the card's own zone (nearest custom-zone
  ancestor, else its board), matching moveCardToZone's lookup, so moving a
  card out of a custom zone back to the board root is offered and the card's
  own zone is disabled

---------

Co-authored-by: Lukas Brübach <Bruebach.Lukas@bdosecurity.de>

cockatrice/src/interface/widgets/tabs/visual_deck_editor/tab_deck_editor_visual.cpp

@@ -4,6 +4,7 @@
 #include "../../../../client/settings/shortcuts_settings.h"
 #include "../../cards/card_info_display_widget.h"
 #include "../../deck_editor/deck_state_manager.h"
+#include "../../deck_editor/deck_zone_dialog.h"
 #include "../../filters/filter_builder.h"
 #include "../../interface/pixel_map_generator.h"
 #include "../../interface/widgets/cards/card_info_frame_widget.h"
@@ -84,6 +85,7 @@ void TabDeckEditorVisual::createCentralFrame()
     connect(tabContainer, &TabDeckEditorVisualTabWidget::printingSelectorRequested, this,
             &TabDeckEditorVisual::showPrintingSelector);
     connect(tabContainer, &TabDeckEditorVisualTabWidget::cardInfoRequested, this, &TabDeckEditorVisual::updateCardInfo);
+    tabContainer->visualDatabaseDisplay->setNewZoneCreator([this] { return createNewZone(); });
 
     centralFrame->addWidget(tabContainer);
     setCentralWidget(centralWidget);
@@ -269,6 +271,19 @@ bool TabDeckEditorVisual::actSaveDeckAs()
     return result;
 }
 
+/** @brief Prompts for and creates a new custom deck zone. Returns the name of the created zone. */
+QString TabDeckEditorVisual::createNewZone()
+{
+    QString boardName;
+    const QString zoneName = DeckZoneDialog::promptForNewZone(this, {}, &boardName, [this](const QString &candidate) {
+        return deckStateManager->validateNewZoneName(candidate);
+    });
+    if (!zoneName.isEmpty()) {
+        deckStateManager->createCustomZone(boardName, zoneName);
+    }
+    return zoneName;
+}
+
 /** @brief Refreshes keyboard shortcuts for this tab from settings. */
 void TabDeckEditorVisual::refreshShortcuts()
 {

cockatrice/src/interface/widgets/tabs/visual_deck_editor/tab_deck_editor_visual.h

@@ -165,6 +165,12 @@ public slots:
      */
     bool actSaveDeckAs() override;
 
+    /**
+     * @brief Prompts for and creates a new custom deck zone.
+     * @return The name of the created zone, or an empty string if creation was cancelled.
+     */
+    QString createNewZone();
+
 private:
     /**
      * @brief Sets the deck for this tab and selects the sub-tab to open on