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>

DELETE/scripts/dev-setup.sh

@@ -0,0 +1,24 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+echo "=== Magnum Opus Development Setup ==="
+
+for cmd in mbsync notmuch bun; do
+	if ! command -v "$cmd" &>/dev/null; then
+		echo "ERROR: $cmd is not installed."
+		echo "  brew install isync notmuch bun"
+		exit 1
+	fi
+done
+
+echo "All dependencies found."
+
+MAIL_DIR="${HOME}/Mail/magnumopus-dev"
+mkdir -p "$MAIL_DIR"
+
+echo ""
+echo "Next steps:"
+echo "  1. Configure your IMAP account in backend/.env"
+echo "  2. Run: cd backend && bun run dev"
+echo "  3. Open clients/macos/MagnumOpus.xcodeproj in Xcode"
+echo "  4. Run: bash scripts/dev-sync.sh  (to trigger first sync)"