feat(config): add pool_domain and upgrade dependencies

- Add configurable pool_domain with pool.ntp.org default
- Update Go from 1.23.5 to 1.24.0
- Update golang.org/x/* dependencies
- Add enumer and accessory as tool dependencies
- Update goreleaser to v2.12.3

config/config_accessor.go

@@ -23,6 +23,13 @@ func (c *Config) WebHostname() string {
 	return c.webHostname
 }
 
+func (c *Config) PoolDomain() string {
+	if c == nil {
+		return ""
+	}
+	return c.poolDomain
+}
+
 func (c *Config) Valid() bool {
 	if c == nil {
 		return false