fix: default value for compile time flags

ref vitejs/vite-plugin-vue@ae9d948

Author: sxzz

src/core/index.ts

@@ -266,18 +266,18 @@ export const plugin: UnpluginInstance<Options | undefined, false> =
               dedupe: config.build?.ssr ? [] : ['vue'],
             },
             define: {
-              __VUE_OPTIONS_API__: !!(
-                (options.value.features?.optionsAPI ?? true) ||
-                config.define?.__VUE_OPTIONS_API__
-              ),
-              __VUE_PROD_DEVTOOLS__: !!(
-                options.value.features?.prodDevtools ||
-                config.define?.__VUE_PROD_DEVTOOLS__
-              ),
-              __VUE_PROD_HYDRATION_MISMATCH_DETAILS__: !!(
-                options.value.features?.prodHydrationMismatchDetails ||
-                config.define?.__VUE_PROD_HYDRATION_MISMATCH_DETAILS__
-              ),
+              __VUE_OPTIONS_API__:
+                options.value.features?.optionsAPI ??
+                config.define?.__VUE_OPTIONS_API__ ??
+                true,
+              __VUE_PROD_DEVTOOLS__:
+                (options.value.features?.prodDevtools ||
+                  config.define?.__VUE_PROD_DEVTOOLS__) ??
+                false,
+              __VUE_PROD_HYDRATION_MISMATCH_DETAILS__:
+                (options.value.features?.prodHydrationMismatchDetails ||
+                  config.define?.__VUE_PROD_HYDRATION_MISMATCH_DETAILS__) ??
+                false,
             },
             ssr: {
               // @ts-ignore -- config.legacy.buildSsrCjsExternalHeuristics will be removed in Vite 5