Add runtime locale diagnostics

app/api/site/default-locale/route.ts

@@ -10,6 +10,11 @@ export async function GET() {
     getMaintenanceMode(),
   ]);
 
+  console.info("api:site:default-locale", {
+    defaultLocale: settings.defaultLocale,
+    maintenanceEnabled,
+  });
+
   return NextResponse.json(
     {
       defaultLocale: settings.defaultLocale,

middleware.ts

@@ -40,6 +40,7 @@ function isComingSoonPath(pathname: string) {
 
 async function getSiteRuntimeState(request: NextRequest): Promise<SiteRuntimeState> {
   try {
+    const runtimeStateUrl = new URL("/api/site/default-locale", request.url);
     const response = await fetch(new URL("/api/site/default-locale", request.url), {
       headers: {
         "x-middleware-request": "1",
@@ -48,6 +49,10 @@ async function getSiteRuntimeState(request: NextRequest): Promise<SiteRuntimeSta
     });
 
     if (!response.ok) {
+      console.warn("middleware:getSiteRuntimeState:non-ok", {
+        url: runtimeStateUrl.toString(),
+        status: response.status,
+      });
       return {
         defaultLocale: FALLBACK_LOCALE,
         maintenanceEnabled: false,
@@ -59,11 +64,18 @@ async function getSiteRuntimeState(request: NextRequest): Promise<SiteRuntimeSta
       maintenanceEnabled?: boolean;
     };
 
+    console.info("middleware:getSiteRuntimeState:resolved", {
+      url: runtimeStateUrl.toString(),
+      defaultLocale: data.defaultLocale,
+      maintenanceEnabled: data.maintenanceEnabled,
+    });
+
     return {
       defaultLocale: isSupportedLocale(data.defaultLocale) ? data.defaultLocale : FALLBACK_LOCALE,
       maintenanceEnabled: data.maintenanceEnabled === true,
     };
   } catch {
+    console.error("middleware:getSiteRuntimeState:failed");
     return {
       defaultLocale: FALLBACK_LOCALE,
       maintenanceEnabled: false,