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/Infrastructure/Data/Indexes.cs

@@ -1,4 +1,4 @@
-using MongoDB.Bson;
+using MongoDB.Bson;
 using MongoDB.Driver;
 using MongoDB.Entities;
 
@@ -131,6 +131,9 @@ namespace PrivaPub.Infrastructure.Data
 			await DB.Default.Index<RemoteInstanceSnapshot>().Key(s => s.Host, KeyType.Ascending).Key(s => s.Week, KeyType.Ascending)
 				.Option(o => o.Unique = true).CreateAsync(token);
 			await Plain<RemoteInstanceSnapshot>(token, s => s.Week);
+			await Plain<RemoteInstanceSnapshot>(token, s => s.CdnDomain, s => s.Week);
+			await Plain<RemoteInstanceSnapshot>(token, s => s.Cdn, s => s.Week);
+			await Plain<CdnRangeSet>(token, s => s.Key);
 			await Plain<RemoteInstance>(token, i => i.Seen);
 			await Plain<RemoteInstance>(token, i => i.LastCrawledAt);
 		}