Add remote-chromium.sh and install waypipe in setup-local.sh

Runs Chromium on the home machine with its window drawn on the travel
laptop, so logged-in browser accounts stay on the home machine. Closes
any running instance first, since Chromium's one-process-per-profile
lock would otherwise open the window on the home machine's own screen.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

remote-chromium.sh

@@ -0,0 +1,41 @@
+#!/usr/bin/env bash
+# Run on the travel laptop: closes any Chromium running for you on the remote
+# machine (Chromium allows one process per profile, so a running instance
+# would swallow the new window), then launches it there with its window
+# drawn here.
+#
+# Usage: remote-chromium.sh [--x11]     (default: waypipe)
+# Remote host: $REMOTE_HOST, default teemu-thinkpad-ubuntu
+set -euo pipefail
+
+HOST="${REMOTE_HOST:-teemu-thinkpad-ubuntu}"
+MODE="waypipe"
+[ "${1:-}" = "--x11" ] && MODE="x11"
+
+if [ "$MODE" = "waypipe" ] && ! command -v waypipe >/dev/null 2>&1; then
+  echo "waypipe not installed here - run: sudo apt install waypipe (needed on both machines)"
+  exit 1
+fi
+
+ssh "$HOST" bash -s <<'EOF'
+# snap build (Ubuntu) and the Debian package - matches the browser binary only,
+# not shells/editors that merely mention "chromium"
+PAT='chromium-browser/chrome|/usr/lib/chromium/chromium'
+if pgrep -u "$USER" -f "$PAT" >/dev/null; then
+  echo "Chromium is running on $(hostname) - closing it gracefully..."
+  pkill -TERM -u "$USER" -f "$PAT"
+  for _ in $(seq 1 10); do
+    pgrep -u "$USER" -f "$PAT" >/dev/null || break
+    sleep 1
+  done
+  if pgrep -u "$USER" -f "$PAT" >/dev/null; then
+    echo "Still running after 10s - force killing."
+    pkill -KILL -u "$USER" -f "$PAT"
+  fi
+fi
+EOF
+
+case "$MODE" in
+  waypipe) exec waypipe ssh "$HOST" chromium --ozone-platform=wayland ;;
+  x11)     exec ssh -X "$HOST" chromium ;;
+esac