chore: establish development baseline

crates/bat-patch/src/error.rs

@@ -0,0 +1,22 @@
+//! Patch 错误类型定义
+
+use thiserror::Error;
+
+/// Patch 错误类型
+#[derive(Error, Debug)]
+pub enum PatchError {
+    /// IO 错误
+    #[error("IO error: {0}")]
+    Io(#[from] std::io::Error),
+
+    /// Patch 应用失败
+    #[error("Patch apply failed: {0}")]
+    ApplyFailed(String),
+
+    /// 其他错误
+    #[error(transparent)]
+    Other(#[from] anyhow::Error),
+}
+
+/// Patch Result 类型
+pub type Result<T> = std::result::Result<T, PatchError>;