fix: address the Maps search box by id, and re-prove Phase 5

The Maps omnibox hint rotates: it read "Search here" in the Phase 5 run and
"Try petrol stations, ATMs" in the AUD-128 re-verification, so the recipe's
text match on it failed. The resource id does not rotate.

- internal/ui: add Find/FindID and the "id:" selector; Find dispatches an
  id: selector to the resource id and everything else to text as before.
- internal/recipe: wait/tap/wait_gone/tap_if and the tap helper use Find, so a
  recipe may name a resource id. Guards stay text-only.
- recipes/maps_navigate.recipe: wait/tap id:search_omnibox_text_box.
- tests for the id selector; docs and README updated.

internal/recipe/engine.go

@@ -324,7 +324,7 @@ func executeStep(r *adb.Runner, rec *Recipe, step Step, index int, params map[st
 			if err != nil {
 				return err
 			}
-			matches := h.FindText(args[0], step.Exact)
+			matches := h.Find(args[0], step.Exact)
 			if len(matches) == 0 {
 				sr.Detail = fmt.Sprintf("%q not on screen, skipped", args[0])
 				return nil
@@ -410,7 +410,8 @@ func executeStep(r *adb.Runner, rec *Recipe, step Step, index int, params map[st
 	return sr
 }
 
-// tapByText finds an element by text and taps its centre (FR-4).
+// tapByText finds an element by text and taps its centre (FR-4). The selector
+// may name a resource id with the "id:" prefix.
 //
 // The element is looked up twice: once to wait for it, and again immediately
 // before the tap, so the coordinates come from the newest dump. On a busy
@@ -423,9 +424,9 @@ func tapByText(r *adb.Runner, rec *Recipe, query string, exact bool, timeout tim
 	if err != nil {
 		return err
 	}
-	matches := h.FindText(query, exact)
+	matches := h.Find(query, exact)
 	if len(matches) == 0 {
-		return describeFailure(r, rec, fmt.Errorf("element with text %q disappeared before the tap", query))
+		return describeFailure(r, rec, fmt.Errorf("element matching %q disappeared before the tap", query))
 	}
 	node, err := ui.TapNode(r, matches)
 	if err != nil {