dns/ddclient: add all-inkl.com KAS API DynDNS provider

[cakallie]

Adds a new Python provider for all-inkl.com hosting using the KAS SOAP API (KasApi.wsdl). Supports A and AAAA records, including root (@) and wildcard (*) entries. Credentials are passed per-request (no separate auth step).

• allinkl.py: new provider class AllInkl, service key 'allinkl'
• dialogAccount.xml: show Zone field for service_allinkl
• DynDNS.xml: add allinkl to static service list (ddclient backend fallback)

Important notices
Before you submit a pull request, we ask you kindly to acknowledge the following:

• [ x ] I have read the contributing guide lines at https://github.com/opnsense/plugins/blob/master/CONTRIBUTING.md
• I opened an issue first for non-trivial changes and linked it below.
• [ x ] AI tools were used to create at least part of the code submitted herewith.

If AI was used, please disclose:

• Model used: Claude Sonnet 4.6
• Extent of AI involvement: This change and PR text were prepared with assistance from Claude Sonnet 4.6. The result was tested against the live API of all-inkl.com and the final responsibility for the submission remains with the author.

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Related issue
No prior issue — this is a self-contained new provider.

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Describe the problem
all-inkl.com offers a pure DNS package without a built-in DynDNS feature. Customers who need to keep a DNS A record updated with their current public IP have no native option within OPNsense to do so via the all-inkl.com KAS API.

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Describe the proposed solution
Implements a new ddclient provider (allinkl) that uses the all-inkl.com KAS SOAP API (KasApi.wsdl) to update DNS A/AAAA records directly. Authentication and DNS updates are performed in a single API call per record. The zone is automatically derived from the configured hostname if not explicitly set.

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[AdSchellevis]

@cakallie although I'm not a huge fan fan of the home grown soap string concat, but since this is rather isolated I don't mind that much adding the helper anyway. If you only need a very limited nearly static string to push to the server, it might be better to isolate that in a template file and use normal xml parsing (xml.etree.ElementTree) to parse the responses.

The DynDNS.xml change is the only one that should be applied to prevent offering the option to ddclient.

[AdSchellevis]

this shouldn't be needed for the python implementation as it uses known_services() to figure out the options.

[cakallie]

Thanks for the review!

I've addressed both points:

1. DynDNS.xml: Removed the allinkl entry — you're right, known_services() handles the registration automatically.
2. XML parsing: Replaced all regex-based response parsing with xml.etree.ElementTree. The SOAP envelope construction remains as string concatenation. Specifically:
   - Fault detection in _kas_api() now uses root.find('.//{}Fault') and also catches ET.ParseError for malformed responses
   - _find_record_id() now navigates the XML tree instead of splitting on regex boundaries
   - The update success check uses findall('.//{}value') instead of a regex search

[AdSchellevis]

@cakallie ok, main concern is addressed, as this is a rather low risk change, let's try to add this to a release so others can test and offer feedback as well.