fix(ui-automation): Report ambiguous gone text waits

Propagate ambiguity from selector-free gone text waits instead of dropping the
recoverable error and timing out. This keeps gone text waits aligned with
textContains when partial text matches multiple distinct elements.

Co-Authored-By: Codex <noreply@example.com>

Author: cameroncooke

src/mcp/tools/ui-automation/__tests__/wait_for_ui.test.ts

@@ -460,6 +460,32 @@ describe('Wait for UI Plugin', () => {
     });
   });
 
+  it('returns TARGET_AMBIGUOUS for selector-free gone with ambiguous partial text', async () => {
+    const { executor } = createSequencedExecutor([
+      {
+        success: true,
+        output: hierarchyJson([
+          createNode({ AXLabel: 'Ready' }),
+          createNode({ AXLabel: 'Ready now' }),
+        ]),
+      },
+    ]);
+
+    const result = await runWaitForUi(
+      { simulatorId, predicate: 'gone', text: 'Ready', timeoutMs: 0 },
+      executor,
+    );
+
+    expect(result.didError).toBe(true);
+    expect(result.uiError).toMatchObject({
+      code: 'TARGET_AMBIGUOUS',
+      candidates: [
+        expect.objectContaining({ label: 'Ready' }),
+        expect.objectContaining({ label: 'Ready now' }),
+      ],
+    });
+  });
+
   it('succeeds for gone when selector matches remain but none contain text', async () => {
     const { executor } = createSequencedExecutor([
       {

src/mcp/tools/ui-automation/wait_for_ui.ts

@@ -198,7 +198,7 @@ function evaluateWaitPredicate(args: {
     return {
       matched: (textMatch.candidates ?? []).length === 0,
       candidates: textMatch.candidates ?? [],
-      uiError: undefined,
+      uiError: textMatch.uiError,
     };
   }