Pi port: serial transport, addressed ESP-NOW bridge, port 80

- Run app on Raspberry Pi: serial to ESP32 bridge at 912000 baud, /dev/ttyS0
- Remove ESP-NOW/MicroPython-only code from src (espnow, p2p, wifi, machine/Pin)
- Transport: always send 6-byte MAC + payload; optional to/destination_mac in API and WebSocket
- Settings and model DB use project paths (no root); fix sys.print_exception for CPython
- Preset/settings controllers use get_current_sender(); template paths for cwd=src
- Pipfile: run from src, PORT from env; scripts for port 80 (setcap) and test
- ESP32 bridge: receive 6-byte addr + payload, LRU peer management (20 max), handle ESP_ERR_ESPNOW_EXIST
- Add esp32/main.py, esp32/benchmark_peers.py, scripts/setup-port80.sh, scripts/test-port80.sh

Made-with: Cursor

scripts/setup-port80.sh

@@ -0,0 +1,35 @@
+#!/usr/bin/env bash
+# Allow the app to bind to port 80 without root.
+# Run once: sudo scripts/setup-port80.sh (from repo root)
+# Or: scripts/setup-port80.sh (will prompt for sudo only for setcap)
+
+set -e
+cd "$(dirname "$0")/.."
+REPO_ROOT="$(pwd)"
+# If run under sudo, use the invoking user's pipenv so the venv is found
+if [ -n "$SUDO_USER" ]; then
+  VENV="$(sudo -u "$SUDO_USER" bash -c "cd '$REPO_ROOT' && pipenv --venv" 2>/dev/null)" || true
+else
+  VENV="$(pipenv --venv 2>/dev/null)" || true
+fi
+if [ -z "$VENV" ]; then
+  echo "Run 'pipenv install' first, then run this script again."
+  exit 1
+fi
+PYTHON="${VENV}/bin/python3"
+if [ ! -f "$PYTHON" ]; then
+  PYTHON="${VENV}/bin/python"
+fi
+if [ ! -f "$PYTHON" ]; then
+  echo "Python not found in venv: $VENV"
+  exit 1
+fi
+# Use the real binary (setcap can fail on symlinks or some filesystems)
+REAL_PYTHON="$(readlink -f "$PYTHON" 2>/dev/null)" || REAL_PYTHON="$PYTHON"
+if sudo setcap 'cap_net_bind_service=+ep' "$REAL_PYTHON" 2>/dev/null; then
+  echo "OK: port 80 enabled for $REAL_PYTHON"
+  echo "Start the app with: pipenv run run"
+else
+  echo "setcap failed on $REAL_PYTHON"
+  exit 1
+fi