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/tui/test/regression-sigwinch-kill-eacces.test.ts

@@ -0,0 +1,62 @@
+import assert from "node:assert";
+import { after, describe, it } from "node:test";
+import { refreshTerminalDimensions } from "../src/terminal.ts";
+
+describe("refreshTerminalDimensions", () => {
+	const originalKill = process.kill;
+	const originalPlatform = process.platform;
+
+	it("does not throw when kill(2) returns EACCES for self-signal", () => {
+		Object.defineProperty(process, "platform", { value: "linux" });
+		process.kill = ((): typeof process.kill => {
+			return (pid, _signal) => {
+				if (pid === process.pid) {
+					const err = new Error("kill EACCES") as NodeJS.ErrnoException;
+					err.code = "EACCES";
+					throw err;
+				}
+				return originalKill.call(process, pid, _signal);
+			};
+		})();
+
+		assert.doesNotThrow(() => {
+			refreshTerminalDimensions();
+		});
+	});
+
+	it("does not call kill on win32", () => {
+		Object.defineProperty(process, "platform", { value: "win32" });
+		let killCalled = false;
+		process.kill = ((): typeof process.kill => {
+			return () => {
+				killCalled = true;
+				return true;
+			};
+		})();
+
+		refreshTerminalDimensions();
+
+		assert.strictEqual(killCalled, false, "kill should not be called on win32");
+	});
+
+	it("preserves other error codes", () => {
+		Object.defineProperty(process, "platform", { value: "linux" });
+		process.kill = ((): typeof process.kill => {
+			return () => {
+				const err = new Error("kill EPERM") as NodeJS.ErrnoException;
+				err.code = "EPERM";
+				throw err;
+			};
+		})();
+
+		// EPERM is also ignored - the refresh is best-effort
+		assert.doesNotThrow(() => {
+			refreshTerminalDimensions();
+		});
+	});
+
+	after(() => {
+		process.kill = originalKill;
+		Object.defineProperty(process, "platform", { value: originalPlatform });
+	});
+});