feat: full-screen lock when server access is blocked

Gate admin boot on server_reachable and show server-unavailable overlay on API 503 for SuperAdmin kill switch.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/config-loader.js

@@ -324,6 +324,11 @@
   }
 
   function applyConfig(config) {
+    if (isServerUnreachable(config)) {
+      showServerUnavailable();
+      throw new Error('خطا در برقراری ارتباط با سرور');
+    }
+
     window.__APP_CONFIG__ = config || {};
     window.__CONFIG_READY__ = true;
 
@@ -344,6 +349,25 @@
     }
   }
 
+  function isServerUnreachable(config) {
+    if (!config || typeof config !== 'object') return false;
+    if (config.server_reachable === false) return true;
+    if (config.user && config.user.server_reachable === false) return true;
+    return false;
+  }
+
+  function showServerUnavailable() {
+    var appRoot = document.querySelector('#app') || document.body;
+    appRoot.innerHTML =
+      '<div style="min-height:100vh;display:flex;align-items:center;justify-content:center;direction:rtl;font-family:sans-serif;padding:24px;background:#fff;color:#111827;">' +
+      '<div style="width:min(420px,100%);text-align:center;border:1px solid rgba(15,23,42,0.08);border-radius:24px;padding:28px 22px;">' +
+      '<div style="font-size:42px;margin-bottom:12px;">⚠️</div>' +
+      '<h2 style="margin:0 0 12px;font-size:20px;">خطا در برقراری ارتباط با سرور</h2>' +
+      '<p style="margin:0 0 20px;color:rgba(15,23,42,0.62);line-height:2;font-size:14px;">لطفاً چند لحظه دیگر دوباره تلاش کنید.</p>' +
+      '<button type="button" onclick="location.reload()" style="padding:11px 22px;border:0;border-radius:12px;background:#2563eb;color:#fff;cursor:pointer;font-weight:700;">تلاش مجدد</button>' +
+      '</div></div>';
+  }
+
   function finishConfigLoad(config, error) {
     if (configResolve) {
       configResolve(config);
@@ -406,15 +430,24 @@
       console.log('Config loaded successfully from', url, config);
       finishConfigLoad(config);
     } catch (error) {
+      if (error && String(error.message || '').includes('خطا در برقراری ارتباط با سرور')) {
+        showServerUnavailable();
+        return;
+      }
       console.warn('Config loader: Could not fetch config from any endpoint');
       console.warn('Error details:', error && error.message ? error.message : error);
       console.warn('App will continue with empty/cached config.');
 
       const cachedConfig = readCachedAppConfig();
       if (cachedConfig) {
-        applyConfig(cachedConfig);
-        finishConfigLoad(cachedConfig, error);
-        return;
+        try {
+          applyConfig(cachedConfig);
+          finishConfigLoad(cachedConfig, error);
+          return;
+        } catch (blockedError) {
+          showServerUnavailable();
+          return;
+        }
       }
 
       window.__APP_CONFIG__ = {};
@@ -439,6 +472,10 @@
     if (!mainScriptLoaded) {
       console.warn('Config loader: Timeout reached. Loading main.ts with empty/cached config.');
       const cachedConfig = readCachedAppConfig();
+      if (isServerUnreachable(cachedConfig) || isServerUnreachable(window.__APP_CONFIG__)) {
+        showServerUnavailable();
+        return;
+      }
       window.__APP_CONFIG__ = cachedConfig || window.__APP_CONFIG__ || {};
       window.__CONFIG_READY__ = true;