chore: 初始化 BlockFlow Workbench 仓库

建立前端与 Tauri 桌面端的首个版本提交，包含核心编辑器、项目文件读写、测试与构建配置。

补充 Git 忽略规则和换行规范，排除依赖、构建产物、本地运行日志与临时验证文件，方便在其他电脑继续开发。

src-tauri/Cargo.toml

@@ -0,0 +1,14 @@
+[package]
+name = "blockflow-workbench"
+version = "0.1.0"
+description = "BlockFlow Workbench desktop shell"
+authors = ["BlockFlow Workbench"]
+edition = "2021"
+
+[build-dependencies]
+tauri-build = { version = "2", features = [] }
+
+[dependencies]
+tauri = { version = "2", features = [] }
+tauri-plugin-dialog = "2"
+tauri-plugin-fs = "2"