feat(cmdcore): suppress interactive prompt off-terminal, document agent protocol

Align the write-confirmation UX with lark-cli: ConfirmRisk (and the
shortcut confirmRisk) now print the yes/no prompt only when stdin is a
real terminal (ioctl-level check via go-isatty; a char-device stat would
misclassify `< /dev/null`). Non-interactive callers get a clean
structured confirmation_required error on stderr. Piped answers are
still honored for humans/scripts; --yes/--dry-run remain the sanctioned
non-interactive paths.

skills/mono: add the recognition + retry protocol for agents —
identify confirmation_required via error.reason, show action and params,
retry the original command with --yes only after explicit user consent,
never silently append --yes or treat it as a transient error.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Co-authored-by: Cursor <cursoragent@cursor.com>

internal/shortcut/shortcut_test.go

@@ -74,8 +74,11 @@ func TestCrossPlatformCoverageConfirmRiskPromptsForStaticWrite(t *testing.T) {
 	if ok, err := confirmRisk(rt, s); err != nil || !ok {
 		t.Fatalf("static write risk was not confirmed: ok=%v err=%v", ok, err)
 	}
-	if got := stderr.String(); !strings.Contains(got, "chat +messages-send（write）") {
-		t.Fatalf("confirmation prompt = %q", got)
+	// A pipe is not a terminal: the prompt must be suppressed (the structured
+	// error carries the semantics for non-interactive callers), while the
+	// piped answer is still honored.
+	if got := stderr.String(); got != "" {
+		t.Fatalf("non-terminal stdin must not print a prompt, got %q", got)
 	}
 }