Located posts: local only, rounded, matched against their own radius

A post given a latitude and longitude becomes LocalGeo: its position is
rounded to two decimals (about a kilometre) and stored as a 2dsphere
point, its radius clamped to 1-50 km, and it is local only - no Create,
no delivery, no outbox, never in the Mastodon API or on a profile page.
/clientapi/post/nearby takes the viewer's position for the query only
(it is neither stored nor logged), runs $geoNear and keeps posts within
each post's own radius, minus authors the viewer blocks or mutes. A
located post cannot be direct or in a group.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012CzABvBkbcFqoHdmi8b9WB

PrivaPub/Domain/Statuses/StatusService.cs

@@ -36,6 +36,9 @@ namespace PrivaPub.Domain.Statuses
 		public string ConversationId { get; init; }
 		public IReadOnlyList<string> Recipients { get; init; } = Array.Empty<string>();
 		public IReadOnlyList<string> MediaIds { get; init; }
+		public double? Latitude { get; init; }
+		public double? Longitude { get; init; }
+		public double? RangeKm { get; init; }
 	}
 
 	public sealed record StatusOutcome(PostEntity Post, int Status = StatusCodes.Status200OK, string Error = default)
@@ -102,9 +105,16 @@ namespace PrivaPub.Domain.Statuses
 			if (parent != default && !await VisibilityPolicy.CanSee(parent, author.Id, token))
 				return StatusOutcome.Fail(StatusCodes.Status404NotFound, "Record not found");
 
+			var located = draft.Latitude.HasValue || draft.Longitude.HasValue;
+			if (located && (draft.Latitude is not (>= -90 and <= 90) || draft.Longitude is not (>= -180 and <= 180) || group != default
+				|| draft.Visibility == PostVisibility.Direct))
+				return StatusOutcome.Fail(StatusCodes.Status422UnprocessableEntity, "Validation failed: A located post needs a valid position and no group or recipients");
+
 			var rendered = draft.PlainText ? await _content.PlainText(draft.Text ?? string.Empty, token) : await _content.Markdown(draft.Text ?? string.Empty, token);
-			var isLocalOnly = group is { IsFederated: false };
-			var visibility = isLocalOnly ? PostVisibility.Circle : draft.Visibility is PostVisibility.Circle or PostVisibility.LocalGeo ? PostVisibility.Public : draft.Visibility;
+			var isLocalOnly = group is { IsFederated: false } || located;
+			var visibility = located ? PostVisibility.LocalGeo
+				: isLocalOnly ? PostVisibility.Circle
+				: draft.Visibility is PostVisibility.Circle or PostVisibility.LocalGeo ? PostVisibility.Public : draft.Visibility;
 			var post = new PostEntity
 			{
 				GroupUserId = author.Id,
@@ -130,6 +140,11 @@ namespace PrivaPub.Domain.Statuses
 			post.ID = (string)post.GenerateNewID();
 			post.ObjectURI = author.PostUri(post.ID);
 			post.Url = author.PostHtmlUrl(post.ID);
+			if (located)
+			{
+				post.Geo = new Coordinates2D(Math.Round(draft.Longitude.Value, 2), Math.Round(draft.Latitude.Value, 2));
+				post.RangeKm = (float)Math.Clamp(draft.RangeKm ?? 5, 1, 50);
+			}
 
 			JsonObject create = default;
 			if (visibility == PostVisibility.Direct)