Simplify character dossier fields, add ShowPronouns setting

Collapse Want/Need into Motivation and Internal/External Conflict into
Conflict, drop Arc summary field, and move tags below open questions on
the character page. Gate Pronouns display behind new UiSettings:ShowPronouns
config (default off).

src/Novelly.Api/Characters/Character.cs

@@ -26,14 +26,9 @@ public class Character
     public string? Personality { get; set; }
     public string? Backstory { get; set; }
 
-    public string? Want { get; set; }
+    public string? Motivation { get; set; }
 
-    public string? Need { get; set; }
-
-    public string? InternalConflict { get; set; }
-    public string? ExternalConflict { get; set; }
-
-    public string? ArcSummary { get; set; }
+    public string? Conflict { get; set; }
 
     public string? Voice { get; set; }