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/agent/test/harness/adaptive-publisher.test.ts

@@ -0,0 +1,76 @@
+import { afterEach, describe, expect, it, vi } from "vitest";
+import { AdaptivePublisher } from "../../src/harness/utils/adaptive-publisher.ts";
+
+afterEach(() => {
+	vi.useRealTimers();
+});
+
+describe("AdaptivePublisher", () => {
+	it("bounds event count and spaces large publications by encoded size", () => {
+		vi.useFakeTimers();
+		vi.setSystemTime(0);
+		let value = "a";
+		const updates: string[] = [];
+		const publisher = new AdaptivePublisher({
+			snapshot: () => value,
+			update: (_previous, current) => current,
+			measure: (update) => update.length,
+			publish: (update) => updates.push(update),
+			onError: (error) => {
+				throw error;
+			},
+			minIntervalMs: 100,
+			targetBytesPerSecond: 100,
+		});
+
+		publisher.markDirty();
+		value = "x".repeat(100);
+		publisher.markDirty();
+		vi.advanceTimersByTime(100);
+		expect(updates).toEqual(["a", "x".repeat(100)]);
+
+		value = "held";
+		publisher.markDirty();
+		vi.advanceTimersByTime(999);
+		expect(updates).toHaveLength(2);
+		vi.advanceTimersByTime(1);
+		expect(updates).toEqual(["a", "x".repeat(100), "held"]);
+	});
+
+	it("commits its baseline before a consumer throws", () => {
+		vi.useFakeTimers();
+		vi.setSystemTime(0);
+		let value = "a";
+		const updates: Array<{ previous: string | undefined; current: string }> = [];
+		let throwAfterApply = false;
+		const publisher = new AdaptivePublisher({
+			snapshot: () => value,
+			update: (previous, current) => ({ previous, current }),
+			measure: () => 1,
+			publish: (update) => {
+				updates.push(update);
+				if (throwAfterApply) throw new Error("consumer failed after apply");
+			},
+			onError: () => {},
+			minIntervalMs: 100,
+			targetBytesPerSecond: 100,
+		});
+
+		publisher.markDirty();
+		vi.advanceTimersByTime(100);
+		value = "ab";
+		throwAfterApply = true;
+		expect(() => publisher.markDirty()).toThrow("consumer failed after apply");
+		publisher.flush(true);
+		expect(updates).toEqual([
+			{ previous: undefined, current: "a" },
+			{ previous: "a", current: "ab" },
+		]);
+
+		throwAfterApply = false;
+		vi.advanceTimersByTime(100);
+		value = "abc";
+		publisher.markDirty();
+		expect(updates.at(-1)).toEqual({ previous: "ab", current: "abc" });
+	});
+});