Enhancement: Normalize DNS names at write-time and eliminate fallback scans

[joyider]

Summary

The memory store currently performs fallback case-insensitive scans when exact lookups fail.

Problem

Read-path lookups may iterate over record collections to find case-insensitive matches.

This increases CPU usage and adds avoidable work to every query.

Proposed solution

Normalize all stored names during write operations.

Suggested normalization:

strings.ToLower(dns.Fqdn(name))

After normalization, lookups can rely entirely on exact key matches.

Remove fallback case-insensitive scans from query processing.

Expected benefits

• Faster record lookups
• Reduced CPU usage
• Simpler lookup logic
• Better scalability

Priority

Medium