feat(chrome): translate legacy string selectors to CSS/XPath

TapSelector now maps id:/desc:/descPrefix:/testTag:/etc. through
TranslateStringSelector. Unknown prefixes pass through to a CSS
attribute selector so a future Maestro key works without a release.

internal/driver/chrome/translate_test.go

@@ -0,0 +1,65 @@
+package chrome
+
+import "testing"
+
+func TestTranslateStringSelector_KnownKeys(t *testing.T) {
+	cases := []struct {
+		selector string
+		want     string
+		isXPath  bool
+	}{
+		{"id:email", `[id="email"]`, false},
+		{"resource-id:account-name", `[id="account-name"]`, false},
+		{"class:btn-primary", `.btn-primary`, false},
+		{"tag:button", `button`, false},
+		{"text:Sign in", `//*[normalize-space(text())="Sign in"]`, true},
+		{"desc:logout", `[aria-label="logout"]`, false},
+		{"label:logout", `[aria-label="logout"]`, false},
+		{"accessibilityLabel:logout", `[aria-label="logout"]`, false},
+		{"aria-label:Sign in", `[aria-label="Sign in"]`, false},
+		{"descPrefix:account:", `[aria-label^="account:"]`, false},
+		{"testTag:submit", `[data-testid="submit"]`, false},
+		{"testID:submit", `[data-testid="submit"]`, false},
+		{"placeholder:Email", `[placeholder="Email"]`, false},
+	}
+	for _, testCase := range cases {
+		got, isXPath, err := TranslateStringSelector(testCase.selector)
+		if err != nil {
+			t.Errorf("%q: unexpected error %v", testCase.selector, err)
+			continue
+		}
+		if got != testCase.want || isXPath != testCase.isXPath {
+			t.Errorf("%q: got (%q, xpath=%v), want (%q, xpath=%v)",
+				testCase.selector, got, isXPath, testCase.want, testCase.isXPath)
+		}
+	}
+}
+
+func TestTranslateStringSelector_UnknownPrefixPassesThrough(t *testing.T) {
+	got, _, err := TranslateStringSelector("role:button")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got != `[role="button"]` {
+		t.Errorf("unknown prefix should map to attribute selector, got %q", got)
+	}
+}
+
+func TestTranslateStringSelector_EscapesQuotes(t *testing.T) {
+	got, _, err := TranslateStringSelector(`label:say "hi"`)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if got != `[aria-label="say \"hi\""]` {
+		t.Errorf("expected escaped quotes, got %q", got)
+	}
+}
+
+func TestTranslateStringSelector_RejectsMissingPrefix(t *testing.T) {
+	if _, _, err := TranslateStringSelector("foo"); err == nil {
+		t.Error("expected error for missing prefix")
+	}
+	if _, _, err := TranslateStringSelector(""); err == nil {
+		t.Error("expected error for empty selector")
+	}
+}