chore(vendor): import pi 0.85.1

Imported as a linear vendor commit so forge rebases do not replay the upstream root tree.

git-subtree-dir: third_party/pi

git-subtree-split: d981de1229ef899957bbe968bc8dcda02a21f477

third_party/pi/packages/coding-agent/test/suite/regressions/7269-cli-end-of-options.test.ts

@@ -0,0 +1,39 @@
+import { fauxAssistantMessage } from "@earendil-works/pi-ai";
+import { afterEach, describe, expect, it } from "vitest";
+import { parseArgs } from "../../../src/cli/args.ts";
+import { createHarness, getUserTexts, type Harness } from "../harness.ts";
+
+describe("issue #7269 CLI end-of-options delimiter", () => {
+	let harness: Harness | undefined;
+
+	afterEach(() => {
+		harness?.cleanup();
+		harness = undefined;
+	});
+
+	it.each(["- summarize the following points for me", "--answer my question briefly"])(
+		"passes %j as a prompt after --",
+		async (prompt) => {
+			const parsed = parseArgs(["-ne", "--no-session", "-p", "--", prompt]);
+			expect(parsed.messages).toEqual([prompt]);
+			expect(parsed.unknownFlags.size).toBe(0);
+			expect(parsed.diagnostics).toEqual([]);
+
+			harness = await createHarness();
+			harness.setResponses([fauxAssistantMessage("ok")]);
+			await harness.session.prompt(parsed.messages[0]);
+			expect(getUserTexts(harness)).toEqual([prompt]);
+		},
+	);
+
+	it("stops parsing options while retaining @file handling", () => {
+		const parsed = parseArgs(["--unknown-flag", "value", "--", "--provider", "openai", "-c", "@prompt.md"]);
+
+		expect(parsed.unknownFlags.get("unknown-flag")).toBe("value");
+		expect(parsed.provider).toBeUndefined();
+		expect(parsed.continue).toBeUndefined();
+		expect(parsed.messages).toEqual(["--provider", "openai", "-c"]);
+		expect(parsed.fileArgs).toEqual(["prompt.md"]);
+		expect(parsed.diagnostics).toEqual([]);
+	});
+});