DNS over TLS and HTTPS set up in one step

jarl encrypted-dns setup (and the Encrypted DNS page) finds or obtains a
certificate for the host name, checks that nothing else listens on the
DoT and DoH ports at the chosen addresses (offering a free DoH port), and
stages named's tls statement and listeners as one change, keeping port 53
where it was when there was no listen-on, plus the host name's records in
the private views (local to the view in a linked zone). Status shows what
to give Android, Linux, Firefox, Chrome and Windows clients. A tls
statement with missing files is refused (tls_file_missing), and a
certificate named uses can't be deleted. docs/encrypted-dns.md, e2e with
real DoT and DoH queries.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/validation.md

@@ -104,6 +104,12 @@ applied.
 | `dnssec_old_keys` | info | Signing a zone whose key directory still has old keys |
 | `serial_not_higher` | error | An explicit serial on a signed zone must be above the one named has loaded (automatic serials are raised by themselves) |
 
+## TLS
+
+| Code | Severity | Check |
+|------|----------|-------|
+| `tls_file_missing` | error | The files a top-level `tls` statement names (certificate, key, CA) exist: named doesn't load its configuration without them |
+
 ## Linked zones
 
 See [views.md](views.md#linked-zones). Jarl keeps linked zones in step