CLI: add nodes canvas snapshot + duration parsing

src/cli/parse-duration.test.ts

@@ -0,0 +1,21 @@
+import { describe, expect, it } from "vitest";
+
+import { parseDurationMs } from "./parse-duration.js";
+
+describe("parseDurationMs", () => {
+  it("parses bare ms", () => {
+    expect(parseDurationMs("10000")).toBe(10_000);
+  });
+
+  it("parses seconds suffix", () => {
+    expect(parseDurationMs("10s")).toBe(10_000);
+  });
+
+  it("parses minutes suffix", () => {
+    expect(parseDurationMs("1m")).toBe(60_000);
+  });
+
+  it("supports decimals", () => {
+    expect(parseDurationMs("0.5s")).toBe(500);
+  });
+});