Fix check_domains return type annotation

[Copilot]

The check_domains function was annotated to return MXHost, but actually returns a dict with domain check results (single domain) or a list of such dicts (multiple domains).

Changes

• Added DomainCheckResult TypedDict defining the actual return structure with fields: domain, base_domain, dnssec, soa, ns, mx, spf, dmarc, smtp_tls_reporting, mta_sts, and optionally bimi

• Updated return type from -> MXHost to -> Union[DomainCheckResult, list[DomainCheckResult]]

• Updated docstring to document all returned fields instead of the incomplete list

• Imported result types from submodules to properly type the DomainCheckResult fields

Example

from checkdmarc import check_domains, DomainCheckResult

# Single domain returns DomainCheckResult
result: DomainCheckResult = check_domains(["example.com"])

# Multiple domains returns list[DomainCheckResult]
results: list[DomainCheckResult] = check_domains(["example.com", "example.org"])

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• vmc.digicert.com
  • Triggering command: /usr/bin/python3 python3 tests.py (dns block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

Original prompt

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This section details on the original issue you should resolve

<issue_title>Wrong return type for check_domains</issue_title>
<issue_description>Hi @seanthegeek! Thank you for all the hard work you put into checkdmarc!

I see that in the latest release you've changed the return type for check_domains from Union[OrderedDict, list[OrderedDict[str, Any]]] to MXHost (555f133#diff-621a373ad93038ada7a8c93a25a59ade50b5b73874219dcd0f803c86cc6ff267L64) but this looks like an error because the function can still return a list if more than a single domain was provided and also MXHost doesn't seem to be the correct type even when the function does return a dict.

I'm happy to open a PR that reverts the change or I can also take a stab at trying to come up with a proper TypedDict definition for the function, let me know!

Happy holidays!</issue_description>

<agent_instructions>Update the return type and/or create new typedicts as needed to solve this issue.</agent_instructions>

Comments on the Issue (you are @copilot in this section)

• Fixes Wrong return type for check_domains #228

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