fix(discord): cast COUNT to int for slash command list query

PostgreSQL COUNT() returns bigint, but DiscordSessionListItemDto expects
int for PlayerCount and WaitlistCount. Dapper 2.1.72 in GmRelay.DiscordBot
(without Dapper.AOT) fails to materialize the record with bigint→int mismatch.
Added ::int casts to both COUNT expressions.

Bump version to 3.0.6.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

src/GmRelay.DiscordBot/Features/Sessions/DiscordListSessionsHandler.cs

@@ -21,8 +21,8 @@ public sealed class DiscordListSessionsHandler(NpgsqlDataSource dataSource)
         var sessions = await connection.QueryAsync<DiscordSessionListItemDto>(
             @"SELECT s.id as Id, s.title as Title, s.scheduled_at as ScheduledAt, s.status as Status,
                      s.max_players as MaxPlayers,
-                     COUNT(sp.id) FILTER (WHERE sp.is_gm = false AND sp.registration_status = @Active) as PlayerCount,
-                     COUNT(sp.id) FILTER (WHERE sp.is_gm = false AND sp.registration_status = @Waitlisted) as WaitlistCount
+                     COUNT(sp.id) FILTER (WHERE sp.is_gm = false AND sp.registration_status = @Active)::int as PlayerCount,
+                     COUNT(sp.id) FILTER (WHERE sp.is_gm = false AND sp.registration_status = @Waitlisted)::int as WaitlistCount
               FROM sessions s
               JOIN game_groups g ON s.group_id = g.id
               LEFT JOIN session_participants sp ON s.id = sp.session_id

src/GmRelay.Web/Components/Layout/NavMenu.razor

@@ -73,7 +73,7 @@
                     </button>
                 </form>
 
-                <div class="nav-version">v3.0.5</div>
+                <div class="nav-version">v3.0.6</div>
             </div>
         </Authorized>
         <NotAuthorized>