chore(vendor): import pi 1.3.0

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: 71023aec1546d6d677a65669c5665c0927ce0dd0

third_party/pi/packages/coding-agent/src/utils/wsl.ts

@@ -0,0 +1,15 @@
+import { readFileSync } from "node:fs";
+
+/** Windows Subsystem for Linux, where Windows executables are reachable through interop. */
+export function isWSL(env: NodeJS.ProcessEnv = process.env): boolean {
+	if (env.WSL_DISTRO_NAME || env.WSLENV) {
+		return true;
+	}
+
+	try {
+		const release = readFileSync("/proc/version", "utf-8");
+		return /microsoft|wsl/i.test(release);
+	} catch {
+		return false;
+	}
+}