Fix start.sh: use python3, drop --reload, cleaner startup output

manager/start.sh

@@ -3,17 +3,23 @@ set -e
 
 cd "$(dirname "$0")"
 
+# Bootstrap virtualenv on first run
 if [ ! -d ".venv" ]; then
   echo "Creating virtualenv..."
-  python3.12 -m venv .venv
+  python3 -m venv .venv
+  .venv/bin/pip install -q --upgrade pip
   .venv/bin/pip install -q -r requirements.txt
 fi
 
 mkdir -p data/bots
 
+# Set token — override via: MANAGER_TOKEN=mysecret ./start.sh
 export MANAGER_TOKEN="${MANAGER_TOKEN:-changeme}"
 
-echo "Starting SimpleX Manager on http://0.0.0.0:8000"
+echo ""
+echo "  SimpleX Manager"
+echo "  URL:   http://0.0.0.0:8000"
 echo "  Token: $MANAGER_TOKEN"
+echo ""
 
-exec .venv/bin/uvicorn main:app --host 0.0.0.0 --port 8000 --reload
+exec .venv/bin/uvicorn main:app --host 0.0.0.0 --port 8000