fix(pi): add snap node compatibility diagnostics and documentation

- Added detailed error logging to detect snap node compatibility issues
- When Pi process exits with code 1, log helpful diagnostic info including node path
- Add hint to check for snap node and reinstall via apt/nvm
- Create SNAP_NODE_COMPATIBILITY.md with full troubleshooting guide
- Document root cause: snap node has file descriptor incompatibility with Bun.spawn stdin pipes
- Provide clear installation instructions for NodeSource and nvm alternatives

scripts/setup-pty-sidecar.sh

@@ -0,0 +1,57 @@
+#!/bin/bash
+# Officer PTY Sidecar — systemd service setup
+# Creates and enables a systemd service for the terminal PTY sidecar.
+# Usage: bash scripts/setup-pty-sidecar.sh
+
+set -euo pipefail
+
+GREEN='\033[0;32m'
+YELLOW='\033[1;33m'
+NC='\033[0m'
+
+ok()   { echo -e "  ${GREEN}✓${NC} $1"; }
+warn() { echo -e "  ${YELLOW}!${NC} $1"; }
+skip() { echo -e "  - $1 (already set up)"; }
+
+SERVICE_NAME="officer-pty-sidecar"
+SERVICE_FILE="/etc/systemd/system/${SERVICE_NAME}.service"
+SERVICE_USER="$(whoami)"
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+PROJECT_DIR="$(dirname "$SCRIPT_DIR")"
+NODE_BIN="$(which node)"
+
+echo ""
+echo "── PTY Sidecar (systemd service) ──"
+
+if systemctl is-active --quiet "$SERVICE_NAME" 2>/dev/null; then
+  skip "$SERVICE_NAME service already running"
+  echo "  Use 'bun run restart:sidecar' to restart"
+  exit 0
+fi
+
+sudo tee "$SERVICE_FILE" > /dev/null << EOF
+[Unit]
+Description=Officer PTY Sidecar
+After=network.target
+
+[Service]
+Type=simple
+User=$SERVICE_USER
+WorkingDirectory=$PROJECT_DIR
+Environment=TERMINAL_PTY_PORT=5338
+ExecStart=$NODE_BIN $PROJECT_DIR/src/servers/api/terminal/pty-sidecar.mjs
+Restart=on-failure
+RestartSec=3
+
+[Install]
+WantedBy=multi-user.target
+EOF
+
+sudo systemctl daemon-reload
+sudo systemctl enable --now "$SERVICE_NAME"
+
+if systemctl is-active --quiet "$SERVICE_NAME"; then
+  ok "$SERVICE_NAME service installed and running"
+else
+  warn "$SERVICE_NAME service failed to start — check 'journalctl -u $SERVICE_NAME'"
+fi