Improve check-isp.rsc documentation and code formatting

[gpas45]

Summary

Enhanced the dual-WAN health check script with comprehensive documentation, improved code formatting, and better maintainability without changing core functionality.

Key Changes

• Added detailed header comments explaining the script's purpose, usage, and requirements
• Documented scheduler integration with example configuration
• Added inline comments for each major section (settings, probing, failover logic)
• Improved code formatting with consistent indentation and spacing
• Made configuration more explicit by naming interface variables (Isp1Iface, Isp2Iface) with documented defaults
• Enhanced delay commands with explicit time units (2s instead of 2)
• Standardized comparison operators with consistent spacing (= instead of =)

Implementation Details

• No functional changes to the failover logic or connection tracking behavior
• Configuration variables are now clearly documented at the top of the script
• Comments explain the expected mangle rule naming convention (con-isp1, con-isp2)
• Script remains compatible with existing RouterOS scheduler configurations

https://claude.ai/code/session_015PYMYtCPwvUpUqkfFD5UL6