feat(provider): add ApertoDNS Dynamic DNS provider

[1r0n3d3v3l0per]

Description

Add support for ApertoDNS Dynamic DNS provider.

ApertoDNS implements the ApertoDNS Protocol, a JSON/REST API for Dynamic DNS updates currently submitted to the IETF DNSOP working group as draft-ferro-dnsop-apertodns-protocol.

Implementation

• POST {api_endpoint}/.well-known/apertodns/v1/update
• Bearer token authentication, JSON request and response
• Optional api_endpoint for self-hosted ApertoDNS-compatible servers
• IPv4 and IPv6

Configuration

{
  "settings": [
    {
      "provider": "apertodns",
      "domain": "domain.com",
      "token": "your_api_token",
      "ip_version": "ipv4"
    }
  ]
}

Testing

• go build ./...
• go vet ./...
• gofmt
• go test ./...
• Tested against the live API (success and error paths)

Changes since review

• Removed the DynDNS2 fallback path and its test
• base_url → api_endpoint
• Documentation trimmed to configuration only
• Rebased onto master

[1r0n3d3v3l0per]

Hi @qdm12, just a friendly ping. Let me know if you need any changes. Thank you for your availability.

[qdm12]

Thanks! Sorry I took forever to get to review this PR, life got in the way and all.
If you've moved on from this, feel free to let me know and I can address those comments, I'll push to your branch and merge it so you still get credits for your work.

[1r0n3d3v3l0per]

Rebased onto master and addressed the review. The DynDNS2 fallback is gone, tthe provider now only speaks the modern endpoint, as you suggested. Tested against the live API for both success and error paths.

The only open point is the test structure: I left a note on that thread.