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/registry/src/schema/enums.rs

@@ -618,6 +618,7 @@ pub enum DnsServerBootstrapType {
     Vultr = 68,
     WebSupport = 69,
     YandexCloud = 70,
+    PowerDns = 71,
 }
 
 #[derive(Debug, Clone, Copy, Default, PartialEq, Eq, Hash)]
@@ -694,6 +695,7 @@ pub enum DnsServerType {
     Vultr = 67,
     WebSupport = 68,
     YandexCloud = 69,
+    PowerDns = 70,
 }
 
 #[derive(Debug, Clone, Copy, Default, PartialEq, Eq, Hash)]