feat(system_monitor): Add Network and Disk I/O metrics for observability

[moksha-hub]

Add Network and Disk I/O monitoring capabilities to the system monitor for complete observability of system resources.

Motivation

Currently, the system monitor only tracks CPU, memory, and GPU usage. For real-time applications and performance monitoring, network and disk I/O metrics are essential to understand:

• Network throughput (upload/download rates)
• Disk activity (read/write rates)
• Potential I/O bottlenecks

Proposed Solution

Add the following metrics to system_monitor.rs:

Network I/O

• get_network_tx_rate() — Network transmission rate (bytes/sec)
• get_network_rx_rate() — Network receive rate (bytes/sec)
• get_network_total_rate() — Combined network I/O rate
• format_network_rate() — Human-readable formatting (KB/s, MB/s, GB/s)

Disk I/O

• get_disk_read_rate() — Disk read rate (bytes/sec)
• get_disk_write_rate() — Disk write rate (bytes/sec)
• get_disk_total_rate() — Combined disk I/O rate
• format_disk_rate() — Human-readable formatting

Implementation Details

• Use sysinfo crate's Networks and Disks APIs
• Calculate rates by measuring delta between snapshots
• Store rates in atomic variables for thread-safe access
• Add helper structs NetworkSnapshot and DiskSnapshot

Related

• issue: feat(system_monitor): Add Network and Disk I/O metrics for complete observability #47