fix(desktop): baseline welcome env-id from the atom to avoid immediate-fire false resolve

onWelcome subscribes with `immediate: true`, so the listener fires
synchronously with whatever welcome payload is already in the atom. The
previous code compared against `previousPrimaryEnvId` (descriptor-derived);
if the descriptor hadn't loaded yet, that was null and any non-null current
welcome would resolve the promise instantly, completing the "syncing" stage
before the new backend's welcome actually arrived. Capture the current
welcome's env-id from the atom as the baseline instead so the immediate
fire never matches the "new welcome arrived" predicate.

Author: Jgratton24

apps/web/src/components/settings/ConnectionsSettings.tsx

@@ -86,7 +86,7 @@ import {
   type ServerClientSessionRecord,
   type ServerPairingLinkRecord,
 } from "~/environments/primary";
-import { onWelcome } from "~/rpc/serverState";
+import { getWelcomePayload, onWelcome } from "~/rpc/serverState";
 import { suppressReconnect } from "~/rpc/wsConnectionState";
 import { useStore } from "~/store";
 import type { WsRpcClient } from "~/rpc/wsRpcClient";
@@ -2403,13 +2403,20 @@ export function ConnectionsSettings() {
     const previousPrimaryEnvId = readPrimaryEnvironmentDescriptor()?.environmentId ?? null;
 
     // Subscribe to welcomes BEFORE the swap so we can wait for the new
-    // backend's welcome (env-id !== previous) before declaring the swap done.
+    // backend's welcome before declaring the swap done. Capture the current
+    // welcome's env-id as the baseline instead of comparing against
+    // `previousPrimaryEnvId`: `onWelcome` is `immediate: true` and fires
+    // synchronously with the atom's current value, so if the descriptor
+    // hasn't loaded (`previousPrimaryEnvId === null`) any non-null payload
+    // would otherwise resolve the promise instantly. Using the live welcome
+    // atom as the baseline closes that race.
+    const baselineWelcomeEnvId = getWelcomePayload()?.environment.environmentId ?? null;
     let resolveNewWelcome: (() => void) | null = null;
     const newWelcomePromise = new Promise<void>((resolve) => {
       resolveNewWelcome = resolve;
     });
     const unsubscribeWelcome = onWelcome((payload) => {
-      if (payload.environment.environmentId !== previousPrimaryEnvId) {
+      if (payload.environment.environmentId !== baselineWelcomeEnvId) {
         resolveNewWelcome?.();
       }
     });

apps/web/src/rpc/serverState.ts

@@ -75,6 +75,10 @@ export function getServerConfig(): ServerConfig | null {
   return appAtomRegistry.get(serverConfigAtom);
 }
 
+export function getWelcomePayload(): ServerLifecycleWelcomePayload | null {
+  return appAtomRegistry.get(welcomeAtom);
+}
+
 export function getServerKeybindings(): ServerConfig["keybindings"] {
   return selectKeybindings(getServerConfig());
 }