feat: complete nx9-wg v0.8.0 platform

crates/nx9-wireguard/src/engine.rs

@@ -143,12 +143,25 @@ impl WireGuardEngine for SimulatedWireGuardEngine {
     }
 }
 
-/// Linux Native WireGuard Engine using kernel netlink / interfaces.
+// ── Native Linux WireGuard Engine ─────────────────────────────────────────────
+//
+// On Linux: the real implementation lives in native_linux.rs and uses
+// RTNETLINK + WireGuard Generic Netlink to communicate with the kernel.
+//
+// On non-Linux platforms: a thin simulation wrapper is provided so that
+// the workspace remains portable and tests remain functional.
+
+#[cfg(target_os = "linux")]
+pub use crate::native_linux::NativeLinuxWireGuardEngine;
+
+/// Non-Linux fallback: NativeLinuxWireGuardEngine delegates to simulation.
+#[cfg(not(target_os = "linux"))]
 #[derive(Debug, Clone, Default)]
 pub struct NativeLinuxWireGuardEngine {
     simulated_fallback: SimulatedWireGuardEngine,
 }
 
+#[cfg(not(target_os = "linux"))]
 impl NativeLinuxWireGuardEngine {
     pub fn new() -> Self {
         Self {
@@ -156,24 +169,16 @@ impl NativeLinuxWireGuardEngine {
         }
     }
 
-    /// Check if Linux kernel WireGuard module / interface support is available.
+    /// Check if Linux kernel WireGuard support is available.
     pub fn is_supported() -> bool {
-        #[cfg(target_os = "linux")]
-        {
-            std::path::Path::new("/sys/module/wireguard").exists()
-                || std::path::Path::new("/proc/net/dev").exists()
-        }
-        #[cfg(not(target_os = "linux"))]
-        {
-            false
-        }
+        false
     }
 }
 
+#[cfg(not(target_os = "linux"))]
 #[async_trait::async_trait]
 impl WireGuardEngine for NativeLinuxWireGuardEngine {
     async fn sync_interface(&self, interface: &Interface, peers: &[Peer]) -> Result<()> {
-        // Fallback to simulated engine for test sandboxes and non-root execution
         self.simulated_fallback
             .sync_interface(interface, peers)
             .await