fix(bug): avoid overwriting stored tokens with an empty UI value

GatewayClient.ts:944 → token: "" || undefined = undefined → omitted from patch
mergeGatewayConnectionState: patch.token === undefined → patchedToken = undefined → nextToken = undefined || current?.token ?? "" = "abc123" ✓

scenarionn- user explicitly clears token (empty string patch):

mergeGatewayConnectionState: patchedToken = "" → nextToken = "" || current?.token ?? "" = falls back to existing stored token

Authored By: GSKNNFT

src/lib/gateway/GatewayClient.ts

@@ -943,7 +943,7 @@ export const useGatewayConnection = (
         gateway: {
           lastKnownGood: {
             url: gatewayUrl.trim(),
-            token,
+            token: token || undefined,
             adapterType: nextDetectedAdapterType,
           },
         },

src/lib/studio/settings.ts

@@ -917,8 +917,8 @@ const mergeGatewayConnectionState = (
   const nextUrl =
     patch.url === undefined ? current?.url ?? "" : normalizeGatewayUrl(patch.url);
   if (!nextUrl) return null;
-  const nextToken =
-    patch.token === undefined ? current?.token ?? "" : coerceString(patch.token);
+  const patchedToken = patch.token === undefined ? undefined : coerceString(patch.token);
+  const nextToken = patchedToken || (current?.token ?? "");
   const nextAdapterType =
     patch.adapterType === undefined
       ? current?.adapterType ?? "openclaw"

tests/unit/studioSettings.test.ts

@@ -438,4 +438,81 @@ describe("studio settings normalization", () => {
       token: "",
     });
   });
+
+  it("merging lastKnownGood with an empty-string token does not overwrite a stored token", () => {
+    const current = normalizeStudioSettings({
+      gateway: {
+        url: "ws://localhost:18789",
+        token: "stored-token",
+        lastKnownGood: {
+          url: "ws://localhost:18789",
+          token: "stored-token",
+          adapterType: "openclaw",
+        },
+      },
+    });
+
+    const merged = mergeStudioSettings(current, {
+      gateway: {
+        lastKnownGood: {
+          url: "ws://localhost:18789",
+          token: "",
+          adapterType: "openclaw",
+        },
+      },
+    });
+
+    expect(merged.gateway?.lastKnownGood?.token).toBe("stored-token");
+  });
+
+  it("merging lastKnownGood with a real token overwrites the stored token", () => {
+    const current = normalizeStudioSettings({
+      gateway: {
+        url: "ws://localhost:18789",
+        token: "old-token",
+        lastKnownGood: {
+          url: "ws://localhost:18789",
+          token: "old-token",
+          adapterType: "openclaw",
+        },
+      },
+    });
+
+    const merged = mergeStudioSettings(current, {
+      gateway: {
+        lastKnownGood: {
+          url: "ws://localhost:18789",
+          token: "new-token",
+          adapterType: "openclaw",
+        },
+      },
+    });
+
+    expect(merged.gateway?.lastKnownGood?.token).toBe("new-token");
+  });
+
+  it("merging lastKnownGood with undefined token leaves the stored token unchanged", () => {
+    const current = normalizeStudioSettings({
+      gateway: {
+        url: "ws://localhost:18789",
+        token: "stored-token",
+        lastKnownGood: {
+          url: "ws://localhost:18789",
+          token: "stored-token",
+          adapterType: "openclaw",
+        },
+      },
+    });
+
+    const merged = mergeStudioSettings(current, {
+      gateway: {
+        lastKnownGood: {
+          url: "ws://localhost:18789",
+          adapterType: "openclaw",
+        },
+      },
+    });
+
+    expect(merged.gateway?.lastKnownGood?.token).toBe("stored-token");
+  });
 });