fix(ios): gate get text snapshot-text fast-path to iOS only

Review (P1): the fast-path skipped the backend read on Android/Linux/macOS too,
but those backends read value-first (macOS helper: AXValue→title→description;
Linux similar) whereas snapshot readable text is label-first for non-editables —
so skipping their read changed get text output. Restrict the optimization to the
iOS XCUITest path (the slow allElementsBoundByIndex re-read it targets). Adds a
test asserting non-iOS platforms still dispatch the backend read.

Author: thymikee

src/daemon/handlers/__tests__/interaction-read.test.ts

@@ -54,4 +54,17 @@ describe('readTextForNode', () => {
     expect(text).toBe('General');
     expect(mockDispatch).not.toHaveBeenCalled();
   });
+
+  it('does NOT skip the backend read on non-iOS platforms (value-first read semantics differ)', async () => {
+    for (const platform of ['android', 'macos', 'linux'] as const) {
+      mockDispatch.mockClear();
+      const text = await readTextForNode({
+        ...baseParams,
+        device: { platform } as never,
+        node: node({ type: 'button', label: 'General' }),
+      });
+      expect(mockDispatch).toHaveBeenCalledOnce();
+      expect(text).toBe('backend-text');
+    }
+  });
 });

src/daemon/handlers/interaction-read.ts

@@ -23,13 +23,19 @@ export async function readTextForNode(params: {
     return fallbackText;
   }
 
-  // The backend `read` re-resolves the element at a point, which on iOS XCUITest enumerates
-  // the full element tree (allElementsBoundByIndex) and is ~20x slower than the snapshot we
+  // iOS only: the XCUITest backend `read` re-resolves the element at a point by enumerating
+  // the full element tree (allElementsBoundByIndex), which is ~20x slower than the snapshot we
   // already captured to resolve this node. That re-read only recovers fuller text for
   // editable/expandable inputs (textField/searchField/textView/…), where the live value can
-  // exceed the snapshot. For every other element type the snapshot node text is authoritative,
-  // so return it directly and skip the expensive round-trip.
-  if (fallbackText && !prefersValueForReadableText(node.type ?? '')) {
+  // exceed the snapshot; for every other element type the snapshot node text is authoritative.
+  // Restricted to iOS because other backends read differently — macOS helper and Linux reads
+  // are value-first (AXValue/title/description), unlike the label-first snapshot readable text,
+  // so skipping their backend read would change the returned text.
+  if (
+    device.platform === 'ios' &&
+    fallbackText &&
+    !prefersValueForReadableText(node.type ?? '')
+  ) {
     return fallbackText;
   }