feat: add FastAPI manager API compatibility baseline

main/manager-api-fastapi/scripts/start-api.sh

@@ -0,0 +1,20 @@
+#!/bin/sh
+set -eu
+
+SCRIPT_DIR=$(CDPATH= cd -- "$(dirname -- "$0")" && pwd)
+PROJECT_DIR=$(CDPATH= cd -- "${SCRIPT_DIR}/.." && pwd)
+PYTHON="${PYTHON_BIN:-${PROJECT_DIR}/.venv/bin/python}"
+
+if [ ! -x "${PYTHON}" ]; then
+  echo "Python environment is missing; run 'uv sync --locked' in ${PROJECT_DIR}" >&2
+  exit 1
+fi
+
+cd "${PROJECT_DIR}"
+exec "${PYTHON}" -m uvicorn app.main:app \
+  --host "${APP_HOST:-0.0.0.0}" \
+  --port "${APP_PORT:-8002}" \
+  --workers "${APP_WORKERS:-1}" \
+  --timeout-graceful-shutdown "${APP_GRACEFUL_SHUTDOWN_SECONDS:-30}" \
+  --proxy-headers \
+  --forwarded-allow-ips "${APP_FORWARDED_ALLOW_IPS:-127.0.0.1}"