Add wildcard subdomain matching in config host sections

[ryanfowler]

Support [*.example.com] syntax to match any subdomain of a domain. Exact matches take priority, and when multiple wildcards match, the most specific (longest suffix) wins.

[Copilot]

Pull request overview

This PR adds wildcard subdomain matching support to the host configuration sections, allowing patterns like [*.example.com] to match any subdomain of a domain. Exact hostname matches take priority, and when multiple wildcard patterns match, the most specific (longest suffix) is selected.

Changes:

• Implemented validation for wildcard hostname patterns in the config parser
• Added HostConfig() method to resolve hostname configurations with wildcard matching logic
• Updated configuration lookup to use the new wildcard-aware resolution method

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

File	Description
main.go	Refactored config lookup to use the new HostConfig() method instead of direct map access
internal/config/file.go	Added wildcard validation logic and implemented HostConfig() method for wildcard-aware hostname resolution
internal/config/file_test.go	Added comprehensive test coverage for wildcard validation and hostname matching scenarios
docs/configuration.md	Added documentation explaining wildcard subdomain matching syntax and matching rules

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