feat: rework Electron desktop app to run standalone-first with optional two-way sync to a remote Termix server

src/ui/api/host-metrics-status-api.ts

@@ -1,8 +1,31 @@
 import axios, { type AxiosRequestConfig } from "axios";
-import { handleApiError, statsApi } from "@/main-axios";
+import {
+  handleApiError,
+  statsApi,
+  getRemoteStatsApi,
+  isElectron,
+} from "@/main-axios";
 import type { ServerMetrics, ServerStatus } from "@/main-axios";
 import { getCachedServerStatuses } from "@/lib/hosts-request-cache";
 
+// Metrics collection/viewer registration below (startMetricsPolling,
+// registerMetricsViewer, etc.) is NOT origin-routed: the backend that
+// receives the call must own the target host by numeric database id, and a
+// synced host has a different numeric id in each database (only its
+// syncId matches across them). Only the aggregate status read is merged
+// across local + remote, same as tunnel status.
+async function isRemoteSyncConnected(): Promise<boolean> {
+  if (!isElectron()) return false;
+  try {
+    const config = (await window.electronAPI?.invoke?.(
+      "get-remote-sync-config",
+    )) as { serverUrl?: string } | null;
+    return !!config?.serverUrl;
+  } catch {
+    return false;
+  }
+}
+
 type ApiConnectionLog = {
   type: "info" | "success" | "warning" | "error";
   stage: string;
@@ -76,6 +99,7 @@ export async function getAllServerStatuses(): Promise<
 > {
   return getCachedServerStatuses(async () => {
     let lastError: unknown = null;
+    let localStatuses: Record<number, ServerStatus> = {};
 
     for (let i = 0; i < STATUS_RETRY_SCHEDULE.length; i++) {
       const { timeoutMs, pauseAfterMs } = STATUS_RETRY_SCHEDULE[i];
@@ -89,7 +113,9 @@ export async function getAllServerStatuses(): Promise<
           // blips don't look like real outages.
           __silentRetry: !isFinalAttempt,
         } as AxiosRequestConfig & { __silentRetry?: boolean });
-        return response.data || {};
+        localStatuses = response.data || {};
+        lastError = null;
+        break;
       } catch (error) {
         lastError = error;
         if (!isTransientStatusError(error)) {
@@ -102,8 +128,24 @@ export async function getAllServerStatuses(): Promise<
       }
     }
 
-    handleApiError(lastError, "fetch server statuses");
-    return {};
+    if (lastError) {
+      handleApiError(lastError, "fetch server statuses");
+      return {};
+    }
+
+    if (await isRemoteSyncConnected()) {
+      try {
+        const remoteResult = await getRemoteStatsApi().get("/status", {
+          timeout: 8000,
+          __silentRetry: true,
+        } as AxiosRequestConfig & { __silentRetry?: boolean });
+        return { ...localStatuses, ...(remoteResult.data || {}) };
+      } catch {
+        // remote unreachable this tick -- fall back to local-only statuses
+      }
+    }
+
+    return localStatuses;
   });
 }