feat(drag-reorder): make sort_order property name configurable via settings

The drag-to-reorder feature hardcoded "sort_order" as the frontmatter
property name. This wires it through the existing FieldMapping system
so users can customise it in Settings > Task Properties, just like
every other property.

- sortOrderUtils: replace 3 hardcoded "sort_order" references with
  plugin.settings.fieldMapping.sortOrder
- isSortOrderInSortConfig: accept sortOrderField param so the sort
  config check uses the mapped name
- TaskListView / KanbanView: pass the mapped field name to all
  isSortOrderInSortConfig calls
- taskPropertiesTab: add Sort Order property card in Metadata section
- en.ts: add translation keys for the new settings card

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/bases/KanbanView.ts

@@ -1904,7 +1904,7 @@ export class KanbanView extends BasesViewBase {
 
 			// Compute and write sort_order if we have a drop position
 			// and the view's sort config includes sort_order
-			const hasSortOrder = isSortOrderInSortConfig(this.dataAdapter);
+			const hasSortOrder = isSortOrderInSortConfig(this.dataAdapter, this.plugin.settings.fieldMapping.sortOrder);
 			if (dropTarget && hasSortOrder) {
 				const cleanGroupByForSort = stripPropertyPrefix(groupByPropertyId);
 				for (const path of pathsToUpdate) {

src/bases/TaskListView.ts

@@ -504,7 +504,7 @@ export class TaskListView extends BasesViewBase {
 					const card = createTaskCard(taskInfo, this.plugin, visibleProperties, cardOptions);
 
 					// Attach drag handlers for sort_order reordering
-					if (isSortOrderInSortConfig(this.dataAdapter)) {
+					if (isSortOrderInSortConfig(this.dataAdapter, this.plugin.settings.fieldMapping.sortOrder)) {
 						card.setAttribute("draggable", "true");
 						this.setupCardDragHandlers(card, taskInfo, null);
 					}
@@ -570,7 +570,7 @@ export class TaskListView extends BasesViewBase {
 			}
 
 			// Attach drag handlers when the card was (re)created
-			if (needsUpdate && isSortOrderInSortConfig(this.dataAdapter)) {
+			if (needsUpdate && isSortOrderInSortConfig(this.dataAdapter, this.plugin.settings.fieldMapping.sortOrder)) {
 				cardEl!.setAttribute("draggable", "true");
 				this.setupCardDragHandlers(cardEl!, taskInfo, null);
 			}
@@ -851,7 +851,7 @@ export class TaskListView extends BasesViewBase {
 					} else {
 						const cardEl = createTaskCard(item.task, this.plugin, visibleProperties, cardOptions);
 						// Attach drag handlers for sort_order reordering
-						if (isSortOrderInSortConfig(this.dataAdapter)) {
+						if (isSortOrderInSortConfig(this.dataAdapter, this.plugin.settings.fieldMapping.sortOrder)) {
 							cardEl.setAttribute("draggable", "true");
 							this.setupCardDragHandlers(cardEl, item.task, item.groupKey);
 						}
@@ -898,7 +898,7 @@ export class TaskListView extends BasesViewBase {
 				this.itemsContainer!.appendChild(headerEl);
 			} else {
 				const cardEl = createTaskCard(item.task, this.plugin, visibleProperties, cardOptions);
-				if (isSortOrderInSortConfig(this.dataAdapter)) {
+				if (isSortOrderInSortConfig(this.dataAdapter, this.plugin.settings.fieldMapping.sortOrder)) {
 					cardEl.setAttribute("draggable", "true");
 					this.setupCardDragHandlers(cardEl, item.task, item.groupKey);
 				}

src/bases/sortOrderUtils.ts

@@ -23,7 +23,7 @@ export function stripPropertyPrefix(propertyId: string): string {
  * Check whether `sort_order` is present in the view's base sort configuration.
  * Drag-to-reorder should only activate when this returns true.
  */
-export function isSortOrderInSortConfig(dataAdapter: any): boolean {
+export function isSortOrderInSortConfig(dataAdapter: any, sortOrderField: string): boolean {
 	try {
 		const sortConfig = dataAdapter.getSortConfig();
 		if (!sortConfig) return false;
@@ -36,7 +36,7 @@ export function isSortOrderInSortConfig(dataAdapter: any): boolean {
 			// Check all possible keys the sort property might be under
 			const candidate = s.property || s.column || s.field || s.id || s.name || "";
 			const clean = String(candidate).replace(/^(note\.|file\.|task\.)/, "");
-			return clean === "sort_order";
+			return clean === sortOrderField;
 		});
 	} catch (e) {
 		return false;
@@ -97,8 +97,9 @@ export function getGroupTasks(
 		// When groupKey is null, include ALL tasks (flat/ungrouped mode)
 
 		// Read sort_order
-		const sortOrder = fm["sort_order"] !== undefined
-			? (typeof fm["sort_order"] === "number" ? fm["sort_order"] : Number(fm["sort_order"]))
+		const sortOrderField = plugin.settings.fieldMapping.sortOrder;
+		const sortOrder = fm[sortOrderField] !== undefined
+			? (typeof fm[sortOrderField] === "number" ? fm[sortOrderField] : Number(fm[sortOrderField]))
 			: undefined;
 
 		// Use cached TaskInfo if available, otherwise create minimal object
@@ -179,8 +180,9 @@ async function renumberAndInsert(
 	for (const w of writes) {
 		const file = plugin.app.vault.getAbstractFileByPath(w.path);
 		if (file && file instanceof TFile) {
+			const sortOrderField = plugin.settings.fieldMapping.sortOrder;
 			await plugin.app.fileManager.processFrontMatter(file, (frontmatter) => {
-				frontmatter["sort_order"] = w.order;
+				frontmatter[sortOrderField] = w.order;
 			});
 		}
 	}

src/i18n/resources/en.ts

@@ -985,6 +985,11 @@ export const en: TranslationTree = {
 					description:
 						"Links to tasks that must be completed before this one. Stored as wikilinks. Blocked tasks display a visual indicator.",
 				},
+				sortOrder: {
+					name: "Sort Order",
+					description:
+						"Frontmatter property used for manual task ordering via drag-and-drop.",
+				},
 				pomodoros: {
 					name: "Pomodoros",
 					description:
@@ -1144,6 +1149,7 @@ export const en: TranslationTree = {
 					timeEntries: "Time entries",
 					completeInstances: "Complete instances",
 					blockedBy: "Blocked by",
+					sortOrder: "Sort order",
 					pomodoros: "Pomodoros",
 					icsEventId: "ICS Event ID",
 					icsEventTag: "ICS Event Tag",

src/settings/tabs/taskPropertiesTab.ts

@@ -207,6 +207,11 @@ export function renderTaskPropertiesTab(
 		translate("settings.taskProperties.properties.blockedBy.name"),
 		translate("settings.taskProperties.properties.blockedBy.description"));
 
+	// Sort Order Property Card
+	renderMetadataPropertyCard(container, plugin, save, translate, "sortOrder",
+		translate("settings.taskProperties.properties.sortOrder.name"),
+		translate("settings.taskProperties.properties.sortOrder.description"));
+
 	// ===== FEATURE PROPERTIES SECTION =====
 	createSectionHeader(container, translate("settings.taskProperties.sections.featureProperties"));
 	createHelpText(container, translate("settings.taskProperties.sections.featurePropertiesDesc"));