Add os.getloadavg() to system_metrics() with (0,0,0) fallback for AttributeError/OSError. Add /proc/uptime parsing for uptime_seconds with float conversion and 0 fallback. Add /proc process counting by iterating numeric entries with OSError exception handling. Add load/uptime_seconds/processes fields to /api/system response with rounded values. Add DOMContentLoaded script to inject #