Where a server is, on the public instance API

/api/privapub/v1/instances/:host gains `geo`, the public projection of a
server's place already decided for public server locations
(PublicGeo.Project): city, coordinates and network for servers reporting
at least 10 users and not behind a CDN, the country otherwise, the CDN's
name for a CDN-fronted one, with DB-IP's attribution. `?host[]=`
answers up to 40 servers at once, and this server describes itself:
its host's address located once a day (SelfLocation), or
Statistics:Geo:Self when the owner sets it.

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

CLAUDE.md

@@ -319,7 +319,12 @@ group www-data and reaches the private mongod; `sudo -u www-data` works too.
   revision. Delivery details reach them through `Arrival.Current`, which `InboxProcessor` sets for the handler's
   duration. A fetched record has no signature, key or `@context` of the activity that caused the fetch (its activity
   fields name that trigger), and every record stores its `Extensions` and `ContextNamespaces` for statistics. The raw form lives outside `Post` so timelines never load it. Read through
-  `/api/privapub/v1/statuses/:id/provenance` and `/api/privapub/v1/instances/:host`.
+  `/api/privapub/v1/statuses/:id/provenance` and `/api/privapub/v1/instances/:host` (or `?host[]=`, up to 40; this
+  server answers too).
+- **A server's place leaves only through `PublicGeo.Project`:** city, coordinates (0.1°) and network for servers
+  reporting at least `Statistics:PublicCityMinUsers` users and not behind a CDN, the country otherwise, the CDN's name
+  for a CDN-fronted one. This server's own place is its host's address located once a day (`SelfLocation`), or
+  `Statistics:Geo:Self` when the owner sets it.
 - **Remote objects are parsed for every shape in `ObjectShapes`:** `url`/`icon`/`image` as a value, an object or an
   array; Markdown `content`; missing `mediaType`s inferred; thumbnails from any of their five places; and the typed
   `Link`, `Video`, `Audio` and `Event` details. A Mastodon API card is built from those, never by fetching the linked page