🤖 Fix browser API handling of failed Results without error property (#393)

_Generated with `cmux`_

## Problem

The web main-server's `HttpIpcMainAdapter` was incorrectly handling
failed Results that don't have an `error` property.

The check required both `success === false` AND `'error' in result`:

```typescript
if (
  result &&
  typeof result === "object" &&
  "success" in result &&
  result.success === false &&
  "error" in result  // <-- This line was the bug
) {
  res.json(result);
  return;
}
res.json({ success: true, data: result });
```

When a handler returned `{ success: false }` without an `error`
property, the check failed and the result was incorrectly wrapped as:

```json
{
  "success": true,
  "data": { "success": false }
}
```

This broke error handling in the frontend - errors from operations like
force workspace deletion weren't being properly communicated.

## Solution

Remove the `'error' in result` requirement. Any Result with `success:
false` should be passed through directly, regardless of whether it has
an `error` property.

## Testing

Added test case in `api.test.ts` to verify Results without error
property are handled correctly.

Author: kylecarbs

src/browser/api.test.ts

@@ -132,4 +132,25 @@ describe("Browser API invokeIPC", () => {
       error: structuredError,
     });
   });
+
+  test("should handle failed Result without error property", async () => {
+    // This tests the fix for the force-deletion bug where results like
+    // { success: false } (without error property) weren't being passed through correctly
+    const mockFetch = createMockFetch({
+      success: false,
+    });
+
+    const invokeIPC = createInvokeIPC(mockFetch);
+
+    const result = await invokeIPC<{ success: boolean; error?: string }>(
+      "WORKSPACE_REMOVE",
+      "test-workspace",
+      { force: false }
+    );
+
+    // Should return the failure result as-is, even without error property
+    expect(result).toEqual({
+      success: false,
+    });
+  });
 });

src/main-server.ts

@@ -36,8 +36,7 @@ class HttpIpcMainAdapter {
           result &&
           typeof result === "object" &&
           "success" in result &&
-          result.success === false &&
-          "error" in result
+          result.success === false
         ) {
           // Pass through failed Result to preserve error structure
           res.json(result);