fix(server): return version details in health and shutdown endpoints

server/src/api/rest.rs

@@ -104,8 +104,16 @@ pub async fn gate_set_handler(
     Ok((axum::http::StatusCode::OK, "Gate state updated."))
 }
 
-pub async fn health_handler() -> &'static str {
-    "OK"
+pub async fn health_handler() -> impl IntoResponse {
+    axum::Json(serde_json::json!({
+        "status": "ok",
+        "version": {
+            "app_version": env!("APP_VERSION"),
+            "cargo_pkg_version": env!("CARGO_PKG_VERSION"),
+            "target_os": std::env::consts::OS,
+            "target_arch": std::env::consts::ARCH,
+        }
+    }))
 }
 
 #[cfg(test)]