caddytls: avoid duplicate automation for wildcard-covered hosts (#7697)

* caddytls: Fix wildcard race in auto-HTTPS launch

When evaluating whether to skip managing an individual subdomain
due to an existing wildcard configuration, we now explicitly consult
the automate loader.

Because Caddy apps can start in any order, relying strictly on the
TLS app's internal management state was non-deterministic if the
HTTP app started first. Checking the automate loader guarantees
predictable behavior since it is fully populated during the
Provision phase, well before any apps are started.

* respond to review comments

1. update requested comment
2. remove personal domain from test
3. add regression test

* remove unnecessary mutex lock

* refactor: -integration test, +explicit cases

* refactor: remove redundant test, add comment

* rename file and add header

* update copyright year