fix(browser): show saved screenshot path

packages/coding-agent/test/tools/render-utils.test.ts

@@ -1,5 +1,7 @@
 import { describe, expect, it } from "bun:test";
-import { dedupeParseErrors, formatParseErrors } from "@oh-my-pi/pi-coding-agent/tools/render-utils";
+import * as os from "node:os";
+import * as path from "node:path";
+import { dedupeParseErrors, formatParseErrors, formatSavedScreenshotLine } from "@oh-my-pi/pi-coding-agent/tools/render-utils";
 
 describe("parse error formatting", () => {
 	it("deduplicates parse errors while preserving order", () => {
@@ -30,3 +32,19 @@ describe("parse error formatting", () => {
 		]);
 	});
 });
+
+describe("browser screenshot path formatting", () => {
+	it("shows home-relative saved paths with tilde shorthand", () => {
+		const filePath = path.join(os.homedir(), "screenshots", "capture.png");
+
+		expect(formatSavedScreenshotLine("image/png", 2048, filePath)).toBe(
+			"Saved: image/png (2.00 KB) to ~/screenshots/capture.png",
+		);
+	});
+
+	it("keeps non-home saved paths unchanged", () => {
+		expect(formatSavedScreenshotLine("image/png", 2048, "/tmp/capture.png")).toBe(
+			"Saved: image/png (2.00 KB) to /tmp/capture.png",
+		);
+	});
+});