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/src/cli.ts

@@ -0,0 +1,6 @@
+#!/usr/bin/env node
+import { setupCli } from "./cli/setup.ts";
+import { main } from "./main.ts";
+
+setupCli();
+main(process.argv.slice(2));