Implement custom portrait generation: update API, UI, and localization to support user-defined prompts for portraits, replacing half-body option with custom variant.

src/HSchool.Server/Api/SchoolEndpoints.cs

@@ -246,7 +246,7 @@ internal static class SchoolEndpoints
 
             if (!PortraitKindParser.TryParse(kind, out var portraitKind))
             {
-                return Problem(StatusCodes.Status400BadRequest, "invalid-query", "kind must be avatar, half, or full.");
+                return Problem(StatusCodes.Status400BadRequest, "invalid-query", "kind must be avatar, custom, or full.");
             }
 
             var lookup = await portraits.EnsurePersonAsync(id, personId, cancellationToken);
@@ -274,6 +274,7 @@ internal static class SchoolEndpoints
             int id,
             string personId,
             string? kind,
+            GeneratePortraitRequest? body,
             PortraitService portraits,
             CancellationToken cancellationToken) =>
         {
@@ -284,7 +285,7 @@ internal static class SchoolEndpoints
 
             if (!PortraitKindParser.TryParse(kind, out var portraitKind))
             {
-                return Problem(StatusCodes.Status400BadRequest, "invalid-query", "kind must be avatar, half, or full.");
+                return Problem(StatusCodes.Status400BadRequest, "invalid-query", "kind must be avatar, custom, or full.");
             }
 
             if (!portraits.IsGenerationEnabled)
@@ -292,7 +293,7 @@ internal static class SchoolEndpoints
                 return Problem(StatusCodes.Status503ServiceUnavailable, "swarmui-not-configured", "SwarmUI is not configured.");
             }
 
-            var result = await portraits.GenerateAsync(id, personId, portraitKind, cancellationToken);
+            var result = await portraits.GenerateAsync(id, personId, portraitKind, body?.PromptExtra, cancellationToken);
             return result.Outcome switch
             {
                 PortraitGenerationOutcome.Succeeded => Results.Created(
@@ -300,8 +301,11 @@ internal static class SchoolEndpoints
                     new PortraitResponse(
                         PortraitKindParser.ToApiValue(portraitKind),
                         result.HasAvatar,
-                        result.HasHalfBody,
-                        result.HasFullBody)),
+                        result.HasCustom,
+                        result.HasFullBody,
+                        result.CustomPortraitPrompt)),
+                PortraitGenerationOutcome.InvalidPrompt =>
+                    Problem(StatusCodes.Status400BadRequest, "invalid-body", "Custom portraits need a non-empty promptExtra up to 2000 characters."),
                 PortraitGenerationOutcome.UnknownPerson =>
                     Problem(StatusCodes.Status404NotFound, "unknown-person", "That person is not in the school."),
                 PortraitGenerationOutcome.NotConfigured =>