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/mini-test.sh

@@ -0,0 +1,46 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+MINI_SRC="$SCRIPT_DIR/packages/coding-agent/src/experimental/mini/main.ts"
+MINI_DIST="$SCRIPT_DIR/packages/coding-agent/dist/experimental/mini/main.js"
+
+# The session server is spawned detached and outlives the TUI, so it keeps running whatever code it
+# started with. Restart it after changing anything under mini/, or the protocol will not match.
+stop_server() {
+  pkill -f "mini/server/entry" 2>/dev/null || true
+  rm -f "${PI_AGENT_DIR:-$HOME/.pi/agent}/experimental/mini.sock"
+}
+
+USE_DIST=false
+ARGS=()
+for arg in "$@"; do
+  case "$arg" in
+    --dist) USE_DIST=true ;;
+    --fresh) stop_server ;;
+    --stop) stop_server; echo "Stopped the mini session server."; exit 0 ;;
+    --help)
+      cat <<'USAGE'
+Usage: ./mini-test.sh [--dist] [--fresh] [--stop] [mini args...]
+
+  --dist    run built output with plain node instead of tsx on sources
+  --fresh   stop the detached session server first, so it picks up your changes
+  --stop    stop the detached session server and exit
+
+Mini args are passed through, for example:
+  ./mini-test.sh --continue
+USAGE
+      exit 0 ;;
+    *) ARGS+=("$arg") ;;
+  esac
+done
+
+if [[ "$USE_DIST" == "true" ]]; then
+  if [[ ! -f "$MINI_DIST" ]]; then
+    echo "No build found. Run: npm run build -w @earendil-works/pi-coding-agent" >&2
+    exit 1
+  fi
+  exec node "$MINI_DIST" ${ARGS[@]+"${ARGS[@]}"}
+fi
+
+exec "$SCRIPT_DIR/node_modules/.bin/tsx" --tsconfig "$SCRIPT_DIR/tsconfig.json" "$MINI_SRC" ${ARGS[@]+"${ARGS[@]}"}