fix: 修复3个P0遗留 — AutoRollback回退/ConfigReloaded序列化/FfiString跨allocator

plugin-sdk/src/lib.rs

@@ -64,6 +64,7 @@ pub enum Message {
         ssid: String,
         ip: String,
     },
+    ConfigReloaded(serde_json::Value),
     ConfigReloadRequest,
     Shutdown,
     PluginReady(String),
@@ -104,6 +105,20 @@ impl FfiString {
             len: 0,
         }
     }
+
+    /// 复制为 Rust String（不释放底层内存）
+    ///
+    /// # Safety
+    /// ptr 必须指向有效的 null-terminated C 字符串
+    pub unsafe fn to_string(&self) -> Option<String> {
+        if self.ptr.is_null() {
+            return None;
+        }
+        unsafe { std::ffi::CStr::from_ptr(self.ptr) }
+            .to_str()
+            .ok()
+            .map(str::to_owned)
+    }
 }
 
 #[repr(C)]
@@ -144,6 +159,7 @@ pub struct PluginVTable {
     pub handle_message:
         unsafe extern "C" fn(handle: PluginHandle, message_json: FfiStr) -> FfiResult,
     pub stop: unsafe extern "C" fn(handle: PluginHandle) -> FfiResult,
+    pub free_string: unsafe extern "C" fn(s: FfiString),
     pub destroy: unsafe extern "C" fn(handle: PluginHandle),
     pub get_capabilities: unsafe extern "C" fn(handle: PluginHandle) -> FfiString,
     pub self_test: unsafe extern "C" fn(handle: PluginHandle) -> FfiString,
@@ -371,6 +387,12 @@ macro_rules! export_plugin {
             }
         }
 
+        unsafe extern "C" fn __showen_free_string(s: $crate::FfiString) {
+            if !s.ptr.is_null() {
+                drop(unsafe { std::ffi::CString::from_raw(s.ptr) });
+            }
+        }
+
         unsafe extern "C" fn __showen_get_capabilities(
             handle: $crate::PluginHandle,
         ) -> $crate::FfiString {
@@ -409,6 +431,7 @@ macro_rules! export_plugin {
             start: __showen_start,
             handle_message: __showen_handle_message,
             stop: __showen_stop,
+            free_string: __showen_free_string,
             destroy: __showen_destroy,
             get_capabilities: __showen_get_capabilities,
             self_test: __showen_self_test,