When shell_exec() is disabled on the server (common in production), the system
operations panel now gracefully falls back to PHP built-in functions:
- gethostname() for hostname instead of shell 'hostname' command
- php_uname() for OS info instead of shell 'uname -a' command
- /proc/uptime parsing or unavailable status for uptime
- disk_free_space() and disk_total_space() for disk usage
- memory_get_usage() and PHP memory limit for memory usage
- Improved parsePhpMemoryLimit() to handle memory limit parsing
This ensures the admin panel shows meaningful information even in restricted
production environments where shell_exec is disabled for security reasons.
- Added System Operations link to Admin dashboard (app/Views/Setting/Admin/index.php)
- Uses load_form_div to load the system operations page inline
- Added SystemOperations library for server status collection and actions
- Tile uses server icon (bi-server) and appears in the admin panel grid
- Link: javascript:load_form_div(base_url('setting/admin/system-ops'), 'maindiv', 'System Operations')
