Add first-seen and last-seen history metadata

[leo1987820]

Closes #1.

Summary

• Track first_seen, last_seen, and seen_count metadata for DNS/HTTP probe results so repeated captures can be correlated across rotating IPs.
• Add CLI support for first-seen and last-seen reporting flags.
• Preserve existing result parsing while adding the history fields to serialized records.

Verification

• python C:\Users\leo19\Documents\Codex\2026-06-24\new-chat\work\dooked-history-metadata-check.py
• git diff --check HEAD~1..HEAD

I could not run the full C++ build locally because this Windows environment does not have cmake or a C++ compiler available in PATH.

Bounty/payment note: the issue says the bounty is $100 USD and asks for PayPal details. I can provide PayPal details privately if this PR is accepted; please point me to the preferred safe channel.

[leo1987820]

Small follow-up note on the second commit (d447bad): I tightened the history comparison path so DNS records are matched by the same fields used for equality (type + case-insensitive rdata) instead of relying on std::binary_search with an equality-style comparator. I also sort persisted/current DNS records by the full matching key before comparing or writing history, which should avoid false missing/new records when a domain has multiple records of the same type.

Verification I could run here:

• static regression probe confirming the risky history std::binary_search calls are gone
• git diff --check on the changed files

I still cannot run the full C++ build in this Windows environment because cmake/a C++ compiler are not available in PATH, but the branch is open to maintainer edits if you want any shape changes before merge.