Import upstream v0.16.24, stripped

Upstream commit: af37a234981722493b74623a983581691d2b70b6
Enterprise-only files removed or emptied: 63
Enterprise-only snippets removed: 118 in 50 files
Dangling module declarations removed: 5
Edits turning enterprise off: 25
Third-party code: 14 files, 0 not in THIRD-PARTY.md
Renamed identifiers: 62 in 18 files
Verification: clean

The same Enterprise footprint as v0.16.23. The build check fails only on
tests/src/directory/issuer.rs, unchanged since v0.16.23: it calls a helper
from upstream's Enterprise-only OIDC test, and tests issuer-based directory
routing, an Enterprise feature. main has never carried it.

crates/common/src/network/dns/update.rs

@@ -961,6 +961,20 @@ impl DnsUpdater {
                 )
                 .map_err(|err| format!("Failed to build DNS updater: {}", err))?,
             }),
+            DnsServer::PowerDns(server) => Ok(DnsUpdater {
+                polling_interval: server.polling_interval.into_inner(),
+                propagation_timeout: server.propagation_timeout.into_inner(),
+                propagation_delay: server.propagation_delay.map(|d| d.into_inner()),
+                ttl: server.ttl.into_inner(),
+                core,
+                updater: dns_update::DnsUpdater::new_pdns(
+                    server.api_key.secret().await?,
+                    server.endpoint,
+                    server.server_id,
+                    server.timeout.into_inner().into(),
+                )
+                .map_err(|err| format!("Failed to build DNS updater: {}", err))?,
+            }),
             DnsServer::Safedns(server) => Ok(DnsUpdater {
                 polling_interval: server.polling_interval.into_inner(),
                 propagation_timeout: server.propagation_timeout.into_inner(),