Pixelfed places: a remote post's own place, shown and never federated again

A Note's `location` that is a Place with coordinates (Pixelfed sends
them as strings) is kept in the new Post.Place and shown as
Status.privapub.place {name, latitude, longitude, country}; an edit
replaces it. An Event's location stays its own `places`, and nothing
renders a place back out. Closes the INTEROP P2 Pixelfed location gap
and the ROADMAP long-tail item.

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

PrivaPub/Federation/Objects/ObjectShapes.cs

@@ -1,4 +1,4 @@
-using PrivaPub.Models.Post;
+using PrivaPub.Models.Post;
 
 using System.Globalization;
 using System.Net;
@@ -293,6 +293,31 @@ namespace PrivaPub.Federation.Objects
 			};
 		}
 
+		//a post's own place, as Pixelfed sends it: a Place with coordinates (numbers, or numbers as strings); an Event's
+		//places are its own (Event)
+		public static PostPlace NotePlace(JsonObject note)
+		{
+			if (Value(note, "type") == "Event")
+				return default;
+			var place = Objects(note["location"]).FirstOrDefault(l => Value(l, "type") == "Place");
+			var latitude = Coordinate(place, "latitude");
+			var longitude = Coordinate(place, "longitude");
+			if (latitude is not (>= -90 and <= 90) || longitude is not (>= -180 and <= 180))
+				return default;
+			return new PostPlace
+			{
+				Name = Text(Value(place, "name"), 200),
+				Latitude = Math.Round(latitude.Value, 4),
+				Longitude = Math.Round(longitude.Value, 4),
+				Country = Text(Value(place, "country"), 100)
+			};
+		}
+
+		static double? Coordinate(JsonObject node, string property) =>
+			Double(node, property) ?? (double.TryParse(Value(node, property), NumberStyles.Float, CultureInfo.InvariantCulture, out var number) && double.IsFinite(number)
+				? number
+				: (double?)null);
+
 		static EventPlace Place(JsonObject location)
 		{
 			var type = Value(location, "type");