CLI: dedupe config validate errors and expose allowed values

src/terminal/safe-text.test.ts

@@ -0,0 +1,12 @@
+import { describe, expect, it } from "vitest";
+import { sanitizeTerminalText } from "./safe-text.js";
+
+describe("sanitizeTerminalText", () => {
+  it("removes C1 control characters", () => {
+    expect(sanitizeTerminalText("a\u009bb\u0085c")).toBe("abc");
+  });
+
+  it("escapes line controls while preserving printable text", () => {
+    expect(sanitizeTerminalText("a\tb\nc\rd")).toBe("a\\tb\\nc\\rd");
+  });
+});

src/terminal/safe-text.ts

@@ -0,0 +1,20 @@
+import { stripAnsi } from "./ansi.js";
+
+/**
+ * Normalize untrusted text for single-line terminal/log rendering.
+ */
+export function sanitizeTerminalText(input: string): string {
+  const normalized = stripAnsi(input)
+    .replace(/\r/g, "\\r")
+    .replace(/\n/g, "\\n")
+    .replace(/\t/g, "\\t");
+  let sanitized = "";
+  for (const char of normalized) {
+    const code = char.charCodeAt(0);
+    const isControl = (code >= 0x00 && code <= 0x1f) || (code >= 0x7f && code <= 0x9f);
+    if (!isControl) {
+      sanitized += char;
+    }
+  }
+  return sanitized;
+}