fix task store wiring: correct directory path, pass to sync coordinator, remove unused stub

- TaskStore directory changed from `tasks-<id>` to `<accountId>/tasks/` per spec
- TaskStore now created before SyncCoordinator and passed as `taskStore:` arg so deferral resurfacing works
- Use `mailStore.databaseWriter` instead of raw `dbPool` for consistency
- Remove unused `deferSelectedItem` stub (all callers use `deferItem(_:until:)` directly)

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

Apps/MagnumOpus/ViewModels/MailViewModel.swift

@@ -121,18 +121,21 @@ final class MailViewModel {
 			)
 		}
 
+		// Set up TaskStore sharing the same database
+		let taskDir = FileManager.default.urls(for: .applicationSupportDirectory, in: .userDomainMask)[0]
+			.appendingPathComponent("MagnumOpus", isDirectory: true)
+			.appendingPathComponent(config.id, isDirectory: true)
+			.appendingPathComponent("tasks", isDirectory: true)
+		let ts = TaskStore(taskDirectory: taskDir, dbWriter: mailStore.databaseWriter)
+		taskStore = ts
+
 		coordinator = SyncCoordinator(
 			accountConfig: config,
 			imapClient: imapClient,
 			store: mailStore,
-			actionQueue: queue
+			actionQueue: queue,
+			taskStore: ts
 		)
-
-		// Set up TaskStore sharing the same database
-		let taskDir = FileManager.default.urls(for: .applicationSupportDirectory, in: .userDomainMask)[0]
-			.appendingPathComponent("MagnumOpus", isDirectory: true)
-			.appendingPathComponent("tasks-\(config.id)", isDirectory: true)
-		taskStore = TaskStore(taskDirectory: taskDir, dbWriter: dbPool)
 	}
 
 	func loadMailboxes(accountId: String) async {
@@ -467,13 +470,6 @@ final class MailViewModel {
 
 	// MARK: - GTD Triage Actions (unified items)
 
-	func deferSelectedItem(until date: Date?) {
-		guard let store, let accountConfig else { return }
-		// Find the currently selected item from the items list
-		// We use the selected thread for emails, or need context for tasks
-		// For now, work with the first selected item concept
-	}
-
 	func deferItem(_ item: ItemSummary, until date: Date?) {
 		guard let store, let accountConfig else { return }
 		do {