refactor: 合并 macOS 桌面打包流程

将 macOS .app 打包直接并入 desktop-build-mac，减少重复的桌面构建入口。\n\n同时移除未实现或已废弃的 desktop-package-* 命令和独立打包脚本，降低维护成本。

Makefile

@@ -5,7 +5,7 @@
 	test-mysql-up test-mysql-down test-mysql test-mysql-quick \
 	frontend-build frontend-dev frontend-test frontend-test-watch frontend-test-coverage frontend-test-e2e frontend-lint frontend-clean \
 	desktop-build desktop-build-mac desktop-build-win desktop-build-linux \
-	desktop-dev desktop-test desktop-package-mac desktop-package-win desktop-package-linux desktop-clean \
+	desktop-dev desktop-test desktop-clean \
 	desktop-prepare-frontend desktop-prepare-embedfs
 
 # ============================================
@@ -172,6 +172,50 @@ desktop-build-mac: desktop-prepare-frontend desktop-prepare-embedfs
 	@echo "🍎 Building macOS..."
 	cd backend && CGO_ENABLED=1 GOOS=darwin GOARCH=arm64 go build -o ../build/nex-mac-arm64 ./cmd/desktop
 	cd backend && CGO_ENABLED=1 GOOS=darwin GOARCH=amd64 go build -o ../build/nex-mac-amd64 ./cmd/desktop
+	@echo "📦 Packaging macOS .app..."
+	mkdir -p build/Nex.app/Contents/MacOS build/Nex.app/Contents/Resources
+	cp build/nex-mac-arm64 build/Nex.app/Contents/MacOS/nex
+	@if [ -f assets/AppIcon.icns ]; then \
+		cp assets/AppIcon.icns build/Nex.app/Contents/Resources/; \
+	else \
+		echo "⚠️  未找到 assets/AppIcon.icns"; \
+	fi
+	@{ \
+		printf '%s\n' '<?xml version="1.0" encoding="UTF-8"?>' \
+			'<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">' \
+			'<plist version="1.0">' \
+			'<dict>' \
+			'    <key>CFBundleDevelopmentRegion</key>' \
+			'    <string>zh_CN</string>' \
+			'    <key>CFBundleExecutable</key>' \
+			'    <string>nex</string>' \
+			'    <key>CFBundleIconFile</key>' \
+			'    <string>AppIcon</string>' \
+			'    <key>CFBundleIdentifier</key>' \
+			'    <string>io.nex.gateway</string>' \
+			'    <key>CFBundleInfoDictionaryVersion</key>' \
+			'    <string>6.0</string>' \
+			'    <key>CFBundleName</key>' \
+			'    <string>Nex Gateway</string>' \
+			'    <key>CFBundleDisplayName</key>' \
+			'    <string>Nex Gateway</string>' \
+			'    <key>CFBundlePackageType</key>' \
+			'    <string>APPL</string>' \
+			'    <key>CFBundleShortVersionString</key>' \
+			'    <string>1.0.0</string>' \
+			'    <key>CFBundleVersion</key>' \
+			'    <string>1.0.0</string>' \
+			'    <key>LSMinimumSystemVersion</key>' \
+			'    <string>10.13</string>' \
+			'    <key>LSUIElement</key>' \
+			'    <true/>' \
+			'    <key>NSHighResolutionCapable</key>' \
+			'    <true/>' \
+			'</dict>' \
+			'</plist>'; \
+	} > build/Nex.app/Contents/Info.plist
+	chmod +x build/Nex.app/Contents/MacOS/nex
+	@echo "✅ macOS app packaged: build/Nex.app"
 
 desktop-build-win: desktop-prepare-frontend desktop-prepare-embedfs
 	@echo "🪟 Building Windows..."
@@ -188,15 +232,6 @@ desktop-dev: desktop-prepare-frontend desktop-prepare-embedfs
 desktop-test:
 	cd backend && go test ./cmd/desktop/... -v
 
-desktop-package-mac:
-	./scripts/build/package-macos.sh
-
-desktop-package-win:
-	@echo "⚠️  Windows packaging not implemented yet"
-
-desktop-package-linux:
-	@echo "⚠️  Linux packaging not implemented yet"
-
 desktop-clean:
 	rm -rf build/ embedfs/assets embedfs/frontend-dist