refactor: remove pgvector configuration as vectors are managed in Qdrant

src/NexusReader.Data/Persistence/AppDbContextFactory.cs

@@ -37,7 +37,7 @@ public class AppDbContextFactory : IDesignTimeDbContextFactory<AppDbContext>
              connectionString = "Host=localhost;Database=nexus_reader;Username=postgres;Password=postgres";
         }
 
-        optionsBuilder.UseNpgsql(connectionString, o => o.UseVector());
+        optionsBuilder.UseNpgsql(connectionString);
 
         return new AppDbContext(optionsBuilder.Options);
     }

src/NexusReader.Infrastructure/DependencyInjection.cs

@@ -35,12 +35,12 @@ public static class DependencyInjection
         if (!string.IsNullOrEmpty(pgConnectionString))
         {
             services.AddDbContextFactory<AppDbContext>(options =>
-                options.UseNpgsql(pgConnectionString, o => o.UseVector()),
+                options.UseNpgsql(pgConnectionString),
                 ServiceLifetime.Scoped);
 
             // Also register a scoped DbContext for repositories that need it
             services.AddDbContext<AppDbContext>(options =>
-                options.UseNpgsql(pgConnectionString, o => o.UseVector()));
+                options.UseNpgsql(pgConnectionString));
         }
         else
         {