Add run.sh to launch AppHost and open the web client

Waits for the Vite dev server to respond on :5173, then opens it in the
default browser via xdg-open/open, falling back to printing the URL.

run.sh

@@ -0,0 +1,25 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+cd "$(dirname "${BASH_SOURCE[0]}")"
+
+export DOTNET_ROOT="${DOTNET_ROOT:-/home/james/.dotnet}"
+
+WEB_URL="http://localhost:5173"
+
+open_browser() {
+  until curl -sf "$WEB_URL" >/dev/null 2>&1; do
+    sleep 1
+  done
+  if command -v xdg-open >/dev/null 2>&1; then
+    xdg-open "$WEB_URL" >/dev/null 2>&1 &
+  elif command -v open >/dev/null 2>&1; then
+    open "$WEB_URL" >/dev/null 2>&1 &
+  else
+    echo "Open $WEB_URL in your browser"
+  fi
+}
+
+open_browser &
+
+dotnet run --project src/Novelly.AppHost