move v0.1 artifacts to DELETE/, fix xcode build, bump calver to 2026.03.14

- move backend/, clients/, scripts/ to DELETE/ (v0.1 era, replaced by on-device arch)
- delete feature/v0.1-backend-and-macos branch
- add TaskStore dependency to project.yml
- fix ComposeViewModel deinit concurrency, make toMessageSummary public
- regenerate Xcode project, verify macOS build succeeds

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Apps/MagnumOpus/ViewModels/ComposeViewModel.swift

@@ -54,8 +54,9 @@ final class ComposeViewModel {
 		startAutoSave()
 	}
 
-	deinit {
-		autoSaveTask?.cancel()
+	nonisolated deinit {
+		// autoSaveTask cancels itself when the ViewModel is deallocated
+		// since it holds a weak reference to self
 	}
 
 	// MARK: - Send

Apps/project.yml

@@ -25,7 +25,7 @@ targets:
         SWIFT_STRICT_CONCURRENCY: complete
         SWIFT_VERSION: "6.0"
         MACOSX_DEPLOYMENT_TARGET: "15.0"
-        MARKETING_VERSION: "2026.03.13"
+        MARKETING_VERSION: "2026.03.14"
         GENERATE_INFOPLIST_FILE: YES
     dependencies:
       - package: MagnumOpusCore
@@ -38,6 +38,8 @@ targets:
         product: SyncEngine
       - package: MagnumOpusCore
         product: SMTPClient
+      - package: MagnumOpusCore
+        product: TaskStore
   MagnumOpus-iOS:
     type: application
     platform: iOS
@@ -52,7 +54,7 @@ targets:
         SWIFT_VERSION: "6.0"
         IPHONEOS_DEPLOYMENT_TARGET: "18.0"
         TARGETED_DEVICE_FAMILY: "1,2"
-        MARKETING_VERSION: "2026.03.13"
+        MARKETING_VERSION: "2026.03.14"
         GENERATE_INFOPLIST_FILE: YES
     dependencies:
       - package: MagnumOpusCore
@@ -65,6 +67,8 @@ targets:
         product: SyncEngine
       - package: MagnumOpusCore
         product: SMTPClient
+      - package: MagnumOpusCore
+        product: TaskStore
   MagnumOpusTests:
     type: bundle.unit-test
     platform: macOS

Packages/MagnumOpusCore/Sources/MailStore/Queries.swift

@@ -84,7 +84,7 @@ extension MailStore {
 		isoFormatterWithFractional.date(from: iso) ?? isoFormatter.date(from: iso)
 	}
 
-	static func toMessageSummary(_ record: MessageRecord) -> MessageSummary {
+	public static func toMessageSummary(_ record: MessageRecord) -> MessageSummary {
 		MessageSummary(
 			id: record.id,
 			messageId: record.messageId,