diff --git a/scripts/hot-dev-bg.sh b/scripts/hot-dev-bg.sh
index cf4baeccbe..10114f04a9 100755
--- a/scripts/hot-dev-bg.sh
+++ b/scripts/hot-dev-bg.sh
@@ -3,7 +3,7 @@
 # Run Pulse hot-dev in a managed background session (macOS/Linux).
 #
 # Usage:
-#   ./scripts/hot-dev-bg.sh start
+#   ./scripts/hot-dev-bg.sh start [--takeover]
 #   ./scripts/hot-dev-bg.sh stop
 #   ./scripts/hot-dev-bg.sh restart
 #   ./scripts/hot-dev-bg.sh status
@@ -38,13 +38,46 @@ is_port_listening() {
   lsof -nP -iTCP:"${port}" -sTCP:LISTEN >/dev/null 2>&1
 }
 
-wait_for_port() {
+listener_pids() {
   local port="$1"
-  local timeout_seconds="${2:-60}"
+  lsof -nP -t -iTCP:"${port}" -sTCP:LISTEN 2>/dev/null | sort -u
+}
+
+process_group_id() {
+  local pid="$1"
+  ps -o pgid= -p "${pid}" 2>/dev/null | tr -d '[:space:]'
+}
+
+process_command() {
+  local pid="$1"
+  ps -o command= -p "${pid}" 2>/dev/null | sed 's/^[[:space:]]*//'
+}
+
+listener_is_managed() {
+  local port="$1"
+  local session_pid="$2"
+  local listener_pid
+
+  [[ -n "${session_pid}" ]] || return 1
+
+  while IFS= read -r listener_pid; do
+    [[ -n "${listener_pid}" ]] || continue
+    if [[ "$(process_group_id "${listener_pid}")" == "${session_pid}" ]]; then
+      return 0
+    fi
+  done < <(listener_pids "${port}")
+
+  return 1
+}
+
+wait_for_managed_listener() {
+  local port="$1"
+  local session_pid="$2"
+  local timeout_seconds="${3:-60}"
   local checks=$((timeout_seconds * 2))
 
   while (( checks > 0 )); do
-    if is_port_listening "${port}"; then
+    if listener_is_managed "${port}" "${session_pid}"; then
       return 0
     fi
     sleep 0.5
@@ -64,11 +97,61 @@ is_running() {
   kill -0 "${pid}" 2>/dev/null
 }
 
+describe_listener() {
+  local port="$1"
+  local session_pid="${2:-}"
+  local found=0
+  local listener_pid pgid owner command
+
+  while IFS= read -r listener_pid; do
+    [[ -n "${listener_pid}" ]] || continue
+    found=1
+    pgid="$(process_group_id "${listener_pid}")"
+    owner="unmanaged"
+    if [[ -n "${session_pid}" && "${pgid}" == "${session_pid}" ]]; then
+      owner="managed"
+    fi
+    command="$(process_command "${listener_pid}")"
+    log "Port ${port}: ${owner} listener pid=${listener_pid} pgid=${pgid:-unknown} cmd=${command:-unknown}"
+  done < <(listener_pids "${port}")
+
+  if [[ "${found}" -eq 1 ]]; then
+    return 0
+  fi
+  return 1
+}
+
+has_any_listener() {
+  local port="$1"
+  local listener_pid
+
+  while IFS= read -r listener_pid; do
+    [[ -n "${listener_pid}" ]] || continue
+    return 0
+  done < <(listener_pids "${port}")
+
+  return 1
+}
+
+has_unmanaged_listeners() {
+  local session_pid="${1:-}"
+  local port
+
+  for port in "${FRONTEND_DEV_PORT}" "${PULSE_DEV_API_PORT}"; do
+    if has_any_listener "${port}" && ! listener_is_managed "${port}" "${session_pid}"; then
+      return 0
+    fi
+  done
+
+  return 1
+}
+
 require_python() {
   command -v python3 >/dev/null 2>&1 || fail "python3 is required"
 }
 
 start_bg() {
+  local takeover="${1:-false}"
   require_python
   mkdir -p "$(dirname "${PID_FILE}")"
   touch "${LOG_FILE}"
@@ -81,6 +164,18 @@ start_bg() {
   # Clear stale PID file before fresh start.
   rm -f "${PID_FILE}"
 
+  if has_unmanaged_listeners ""; then
+    if [[ "${takeover}" != "true" ]]; then
+      log "Unmanaged listeners are already using the dev ports."
+      describe_listener "${FRONTEND_DEV_PORT}" "" || true
+      describe_listener "${PULSE_DEV_API_PORT}" "" || true
+      fail "Refusing to take over unmanaged listeners. Stop them first or rerun with: ./scripts/hot-dev-bg.sh start --takeover"
+    fi
+    log "Taking over existing unmanaged listeners on the dev ports."
+    describe_listener "${FRONTEND_DEV_PORT}" "" || true
+    describe_listener "${PULSE_DEV_API_PORT}" "" || true
+  fi
+
   local pid
   pid="$(
     FRONTEND_DEV_HOST="${FRONTEND_DEV_HOST}" \
@@ -120,15 +215,15 @@ PY
   printf "%s\n" "${pid}" > "${PID_FILE}"
 
   log "Started hot-dev (pid: ${pid})"
-  log "Waiting for backend port ${PULSE_DEV_API_PORT}..."
-  if ! wait_for_port "${PULSE_DEV_API_PORT}" 90; then
+  log "Waiting for managed backend listener on port ${PULSE_DEV_API_PORT}..."
+  if ! wait_for_managed_listener "${PULSE_DEV_API_PORT}" "${pid}" 90; then
     log "Backend did not start. Showing recent logs:"
     tail -n 80 "${LOG_FILE}" || true
     fail "hot-dev startup failed"
   fi
 
-  if ! wait_for_port "${FRONTEND_DEV_PORT}" 90; then
-    log "Backend is up, but frontend port ${FRONTEND_DEV_PORT} is not listening yet."
+  if ! wait_for_managed_listener "${FRONTEND_DEV_PORT}" "${pid}" 90; then
+    log "Backend is up, but a managed frontend listener on port ${FRONTEND_DEV_PORT} is not ready yet."
     log "Check logs with: ./scripts/hot-dev-bg.sh logs"
   fi
 
@@ -168,10 +263,10 @@ stop_bg() {
 }
 
 status_bg() {
+  local managed_pid=""
   if is_running; then
-    local pid
-    pid="$(cat "${PID_FILE}")"
-    log "Running (pid: ${pid})"
+    managed_pid="$(cat "${PID_FILE}")"
+    log "Running (pid: ${managed_pid})"
   else
     log "Not running"
   fi
@@ -195,6 +290,15 @@ status_bg() {
   [[ -n "${backend_code}" ]] || backend_code="000"
   log "Frontend HTTP: ${frontend_code}"
   log "Backend HTTP:  ${backend_code}"
+
+  describe_listener "${FRONTEND_DEV_PORT}" "${managed_pid}" || true
+  describe_listener "${PULSE_DEV_API_PORT}" "${managed_pid}" || true
+
+  if [[ -z "${managed_pid}" ]] && has_unmanaged_listeners ""; then
+    log "Detected unmanaged dev listeners. hot-dev-bg is not managing the current runtime."
+  elif [[ -n "${managed_pid}" ]] && has_unmanaged_listeners "${managed_pid}"; then
+    log "Detected split ownership: managed session is running, but one or more dev ports are owned by another process."
+  fi
 }
 
 logs_bg() {
@@ -207,7 +311,7 @@ usage() {
 Usage: $(basename "$0") <command>
 
 Commands:
-  start
+  start [--takeover]
   stop
   restart
   status
@@ -216,10 +320,31 @@ EOF
 }
 
 main() {
-  case "${1:-}" in
-    start) start_bg ;;
+  local command="${1:-}"
+  local flag="${2:-}"
+  local takeover="false"
+
+  if [[ "${flag}" == "--takeover" ]]; then
+    takeover="true"
+  fi
+
+  case "${command}" in
+    start)
+      if [[ -n "${flag}" && "${flag}" != "--takeover" ]]; then
+        usage
+        exit 1
+      fi
+      start_bg "${takeover}"
+      ;;
     stop) stop_bg ;;
-    restart) stop_bg; start_bg ;;
+    restart)
+      if [[ -n "${flag}" && "${flag}" != "--takeover" ]]; then
+        usage
+        exit 1
+      fi
+      stop_bg
+      start_bg "${takeover}"
+      ;;
     status) status_bg ;;
     logs) logs_bg ;;
     *) usage; exit 1 ;;
diff --git a/scripts/hot-dev.sh b/scripts/hot-dev.sh
index 938b332604..b79f5064ec 100755
--- a/scripts/hot-dev.sh
+++ b/scripts/hot-dev.sh
@@ -10,6 +10,7 @@
 # Environment Variables:
 #   HOT_DEV_USE_PROD_DATA=true   Use /etc/pulse for data (sessions, config, etc.)
 #   HOT_DEV_USE_PRO=true         Build Pro binary (default: true if module available)
+#   HOT_DEV_ALLOW_OSS_FALLBACK=true  Allow fallback to OSS backend when Pro build fails
 #   PULSE_MOCK_MODE=true         Render mock UI data while keeping real metrics history intact
 #   PULSE_DATA_DIR=/path         Override data directory
 #   PULSE_DEV_API_PORT=7655      Backend API port (default: 7655)
@@ -70,6 +71,41 @@ check_dependencies() {
     fi
 }
 
+build_backend_binary() {
+    local build_output
+    PULSE_REPOS_DIR="${PULSE_REPOS_DIR:-${DEFAULT_PULSE_REPOS_DIR}}"
+    PRO_MODULE_DIR="${PULSE_REPOS_DIR}/pulse-enterprise"
+
+    if [[ -d "${PRO_MODULE_DIR}" ]] && [[ ${HOT_DEV_USE_PRO:-true} == "true" ]]; then
+        log_info "Building Pro binary (includes persistent audit logging)..."
+        if build_output=$(cd "${PRO_MODULE_DIR}" && go build -buildvcs=false -o "${ROOT_DIR}/pulse" ./cmd/pulse-enterprise 2>&1); then
+            printf "%s\n" "${build_output}" | grep -v "^#" || true
+            PRO_BUILD_SUCCESS=true
+            return 0
+        fi
+
+        printf "%s\n" "${build_output}" | grep -v "^#" || true
+        if [[ ${HOT_DEV_ALLOW_OSS_FALLBACK:-false} != "true" ]]; then
+            log_error "Pro build failed; refusing to fall back to the OSS backend."
+            log_error "Fix pulse-enterprise or set HOT_DEV_ALLOW_OSS_FALLBACK=true to override this explicitly."
+            PRO_BUILD_SUCCESS=false
+            return 1
+        fi
+
+        log_warn "Pro build failed; HOT_DEV_ALLOW_OSS_FALLBACK=true so hot-dev is falling back to the OSS backend."
+    fi
+
+    if build_output=$(cd "${ROOT_DIR}" && go build -o pulse ./cmd/pulse 2>&1); then
+        printf "%s\n" "${build_output}" | grep -v "^#" || true
+        PRO_BUILD_SUCCESS=false
+        return 0
+    fi
+
+    printf "%s\n" "${build_output}" | grep -v "^#" || true
+    PRO_BUILD_SUCCESS=false
+    return 1
+}
+
 # --- Configuration & Environment ---
 
 load_env_file() {
@@ -273,24 +309,10 @@ cd "${ROOT_DIR}"
 mkdir -p internal/api/frontend-modern/dist
 touch internal/api/frontend-modern/dist/index.html
 
-# Check if Pro module is available and use it for full audit logging support
+# Check if Pro module is available and use it for full audit logging support.
 # Use PULSE_REPOS_DIR env var or default to the parent directory that contains sibling repos.
-PULSE_REPOS_DIR="${PULSE_REPOS_DIR:-${DEFAULT_PULSE_REPOS_DIR}}"
-PRO_MODULE_DIR="${PULSE_REPOS_DIR}/pulse-enterprise"
-if [[ -d "${PRO_MODULE_DIR}" ]] && [[ ${HOT_DEV_USE_PRO:-true} == "true" ]]; then
-    log_info "Building Pro binary (includes persistent audit logging)..."
-    cd "${PRO_MODULE_DIR}"
-    go build -buildvcs=false -o "${ROOT_DIR}/pulse" ./cmd/pulse-enterprise 2>/dev/null || {
-        log_warn "Pro build failed, falling back to standard binary"
-        cd "${ROOT_DIR}"
-        go build -o pulse ./cmd/pulse
-    }
-    cd "${ROOT_DIR}"
-    # Note: PULSE_AUDIT_DIR is set after PULSE_DATA_DIR is determined below
-    PRO_BUILD_SUCCESS=true
-else
-    PRO_BUILD_SUCCESS=false
-    go build -o pulse ./cmd/pulse
+if ! build_backend_binary; then
+    exit 1
 fi
 
 FRONTEND_PORT=${PULSE_DEV_API_PORT}
@@ -565,34 +587,11 @@ log_info "Starting backend file watcher..."
         log_info "🔄 Change detected: $(basename "$changed_file")"
         log_info "Rebuilding backend..."
 
-        # Use the same build logic as the initial build
-        local build_success=0
-        local build_output
-        PULSE_REPOS_DIR="${PULSE_REPOS_DIR:-${DEFAULT_PULSE_REPOS_DIR}}"
-        PRO_MODULE_DIR="${PULSE_REPOS_DIR}/pulse-enterprise"
-        if [[ -d "${PRO_MODULE_DIR}" ]] && [[ ${HOT_DEV_USE_PRO:-true} == "true" ]]; then
-            log_info "Building Pro binary..."
-            if build_output=$(cd "${PRO_MODULE_DIR}" && go build -buildvcs=false -o "${ROOT_DIR}/pulse" ./cmd/pulse-enterprise 2>&1); then
-                printf "%s\n" "${build_output}" | grep -v "^#" || true
-                build_success=1
-            else
-                printf "%s\n" "${build_output}" | grep -v "^#" || true
-            fi
-        fi
-        
-        if [[ $build_success -eq 0 ]]; then
-            if build_output=$(go build -o pulse ./cmd/pulse 2>&1); then
-                printf "%s\n" "${build_output}" | grep -v "^#" || true
-                build_success=1
-            else
-                printf "%s\n" "${build_output}" | grep -v "^#" || true
-            fi
-        fi
-
-        if [[ $build_success -eq 1 ]]; then
+        # Use the same build logic as the initial build.
+        if build_backend_binary; then
             restart_backend
         else
-            log_error "✗ Build failed!"
+            log_error "✗ Build failed; keeping the current backend process running."
         fi
         log_info "Watching for changes..."
     }
diff --git a/scripts/tests/test-hot-dev-bg.sh b/scripts/tests/test-hot-dev-bg.sh
new file mode 100755
index 0000000000..b5acd10e20
--- /dev/null
+++ b/scripts/tests/test-hot-dev-bg.sh
@@ -0,0 +1,129 @@
+#!/usr/bin/env bash
+#
+# Smoke test for scripts/hot-dev-bg.sh managed ownership diagnostics.
+
+set -euo pipefail
+
+ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/../.." && pwd)"
+HOT_DEV_BG="${ROOT_DIR}/scripts/hot-dev-bg.sh"
+
+if [[ ! -x "${HOT_DEV_BG}" ]]; then
+  echo "hot-dev-bg.sh not found or not executable at ${HOT_DEV_BG}" >&2
+  exit 1
+fi
+
+failures=0
+server_pids=()
+
+cleanup() {
+  local pid
+  for pid in "${server_pids[@]:-}"; do
+    kill "${pid}" 2>/dev/null || true
+  done
+}
+trap cleanup EXIT
+
+assert_contains() {
+  local desc="$1"
+  local haystack="$2"
+  local needle="$3"
+
+  if [[ "${haystack}" == *"${needle}"* ]]; then
+    echo "[PASS] ${desc}"
+  else
+    echo "[FAIL] ${desc}" >&2
+    echo "Expected to find: ${needle}" >&2
+    ((failures++))
+  fi
+}
+
+pick_free_port() {
+  python3 - <<'PY'
+import socket
+
+sock = socket.socket()
+sock.bind(("127.0.0.1", 0))
+print(sock.getsockname()[1])
+sock.close()
+PY
+}
+
+start_http_server() {
+  local port="$1"
+  python3 -m http.server "${port}" --bind 127.0.0.1 >/dev/null 2>&1 &
+  local pid=$!
+  server_pids+=("${pid}")
+  sleep 1
+}
+
+test_status_without_runtime() {
+  local frontend_port backend_port output
+  frontend_port="$(pick_free_port)"
+  backend_port="$(pick_free_port)"
+  if [[ "${backend_port}" == "${frontend_port}" ]]; then
+    backend_port="$(pick_free_port)"
+  fi
+
+  output="$(
+    FRONTEND_DEV_HOST=127.0.0.1 \
+    FRONTEND_DEV_PORT="${frontend_port}" \
+    PULSE_DEV_API_HOST=127.0.0.1 \
+    PULSE_DEV_API_PORT="${backend_port}" \
+    "${HOT_DEV_BG}" status
+  )"
+
+  assert_contains "status reports no managed runtime" "${output}" "[hot-dev-bg] Not running"
+  assert_contains "status reports idle frontend port" "${output}" "[hot-dev-bg] Frontend port ${frontend_port} is not listening"
+  assert_contains "status reports idle backend port" "${output}" "[hot-dev-bg] Backend port ${backend_port} is not listening"
+}
+
+test_detects_unmanaged_listeners() {
+  local frontend_port backend_port status_output start_output
+  frontend_port="$(pick_free_port)"
+  backend_port="$(pick_free_port)"
+  if [[ "${backend_port}" == "${frontend_port}" ]]; then
+    backend_port="$(pick_free_port)"
+  fi
+
+  start_http_server "${frontend_port}"
+  start_http_server "${backend_port}"
+
+  status_output="$(
+    FRONTEND_DEV_HOST=127.0.0.1 \
+    FRONTEND_DEV_PORT="${frontend_port}" \
+    PULSE_DEV_API_HOST=127.0.0.1 \
+    PULSE_DEV_API_PORT="${backend_port}" \
+    "${HOT_DEV_BG}" status
+  )"
+
+  assert_contains "status reports unmanaged frontend listener" "${status_output}" "[hot-dev-bg] Port ${frontend_port}: unmanaged listener"
+  assert_contains "status reports unmanaged backend listener" "${status_output}" "[hot-dev-bg] Port ${backend_port}: unmanaged listener"
+  assert_contains "status explains unmanaged runtime ownership" "${status_output}" "[hot-dev-bg] Detected unmanaged dev listeners. hot-dev-bg is not managing the current runtime."
+
+  start_output="$(
+    set +e
+    FRONTEND_DEV_HOST=127.0.0.1 \
+    FRONTEND_DEV_PORT="${frontend_port}" \
+    PULSE_DEV_API_HOST=127.0.0.1 \
+    PULSE_DEV_API_PORT="${backend_port}" \
+    "${HOT_DEV_BG}" start 2>&1
+    printf '\nexit_code=%s' "$?"
+  )"
+
+  assert_contains "start refuses unmanaged takeover by default" "${start_output}" "Refusing to take over unmanaged listeners."
+  assert_contains "start returns failure for unmanaged takeover" "${start_output}" "exit_code=1"
+}
+
+main() {
+  test_status_without_runtime
+  test_detects_unmanaged_listeners
+
+  if (( failures > 0 )); then
+    echo "Total failures: ${failures}" >&2
+    exit 1
+  fi
+
+  echo "hot-dev-bg ownership diagnostics smoke tests passed."
+}
+
+main "$@"