fix(web): hide the server update banner when this app is older

apps/web/src/versionSkew.test.ts

@@ -7,6 +7,7 @@ import {
   buildVersionMismatchDismissalKey,
   dismissVersionMismatch,
   isVersionMismatchDismissed,
+  isClientBehindServer,
   resolveServerConfigVersionMismatch,
   resolveServerSelfUpdateCapability,
   resolveVersionMismatch,
@@ -26,7 +27,10 @@ describe("versionSkew", () => {
     });
   });
 
-  it("reads the server version from config descriptors", () => {
+  it("does not offer a server update when this client is older than the server", () => {
+    expect(
+      isClientBehindServer("0.0.34-nightly.20260814.1090", "0.0.34-nightly.20260814.1092"),
+    ).toBe(true);
     expect(
       resolveServerConfigVersionMismatch({
         environment: {
@@ -42,8 +46,27 @@ describe("versionSkew", () => {
           },
         },
       }),
+    ).toBeNull();
+  });
+
+  it("reads an older server version from config descriptors", () => {
+    expect(
+      resolveServerConfigVersionMismatch({
+        environment: {
+          environmentId: EnvironmentId.make("environment-1"),
+          label: "Remote",
+          platform: {
+            os: "darwin",
+            arch: "arm64",
+          },
+          serverVersion: "0.0.0-old",
+          capabilities: {
+            repositoryIdentity: true,
+          },
+        },
+      }),
     ).toMatchObject({
-      serverVersion: "9.9.9",
+      serverVersion: "0.0.0-old",
     });
   });
 

apps/web/src/versionSkew.ts

@@ -1,4 +1,5 @@
 import type { EnvironmentId, ServerConfig, ServerSelfUpdateCapability } from "@t3tools/contracts";
+import { compareSemverVersions } from "@t3tools/shared/semver";
 import * as Schema from "effect/Schema";
 
 import { APP_VERSION } from "./branding";
@@ -43,10 +44,20 @@ export function resolveVersionMismatch(
   };
 }
 
+export function isClientBehindServer(clientVersion: string, serverVersion: string): boolean {
+  return compareSemverVersions(clientVersion, serverVersion) < 0;
+}
+
 export function resolveServerConfigVersionMismatch(
   serverConfig: Pick<ServerConfig, "environment"> | null | undefined,
 ): VersionMismatch | null {
-  return resolveVersionMismatch(serverConfig?.environment.serverVersion);
+  const mismatch = resolveVersionMismatch(serverConfig?.environment.serverVersion);
+  // The desktop app already surfaces its own update in the sidebar. A newer
+  // server should not look like a server update, or offer a downgrade.
+  if (!mismatch || isClientBehindServer(mismatch.clientVersion, mismatch.serverVersion)) {
+    return null;
+  }
+  return mismatch;
 }
 
 /** The update path the connected server offers, or null when it only

docs/user/updating.md

@@ -1,7 +1,9 @@
 # Keeping T3 Code in Sync
 
 The T3 Code web or desktop app and the server it connects to work best when they use the same
-version. If they do not match, T3 Code shows a warning with the right update option for that server.
+version. If the server is older, T3 Code shows a warning with the right update option for that
+server. If this app is older, the desktop update indicator in the sidebar is the place to update;
+T3 Code does not offer to move the server backward.
 
 ## Where to Find the Update