CDNs found by themselves, and servers followed through time

PrivaPub now finds CDNs three ways, best first: the address ranges the
CDNs publish (Cloudflare, Fastly, Amazon CloudFront, Bunny, Gcore,
Imperva), downloaded daily by CdnUpdater and kept in CdnRangeSet; the
CDN's fingerprint in the responses it already gets from a server
(EdgeHintsHandler on the federation client); and the networks that carry
only a CDN. The fixed ASN list is gone; ASNs shared with plain hosting
(AWS, DataPacket) no longer hide a server. A server's Geo records the
CDN, its domain and how it was found, and weekly snapshots now keep the
city and coordinates too.

Servers through time (ServerPlaces): /instances/:host/history lists a
server's weekly snapshots, a CDN-fronted server's geo names the CDN's
domain and where the server was before it (before_cdn), and
/api/privapub/v1/cdns and /cdns/:domain group servers by CDN with week
by week who joined and who left. Owner decisions recorded in ROADMAP.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LsXgEaXee4GCU1hwYgPJXw

PrivaPub/Models/Jobs/CdnRangeSet.cs

@@ -0,0 +1,15 @@
+using MongoDB.Entities;
+
+namespace PrivaPub.Models.Jobs
+{
+	// The address ranges one CDN publishes, as CdnUpdater last downloaded them: kept, so a restart needs no download and a
+	// failed download keeps the previous list.
+	public class CdnRangeSet : Entity
+	{
+		public string Key { get; set; }//the CDN's domain (CdnProvider.Key)
+		public string Name { get; set; }
+		public List<string> Ranges { get; set; } = new();
+		public List<string> Sources { get; set; } = new();
+		public DateTime FetchedAt { get; set; }
+	}
+}