feat: refactor tournament to generic DB-backed N-person bracket

Replace hardcoded 6-person tournament with a generic single-elimination
bracket system backed by new DB tables (tournaments, tournament_entries,
tournament_matches). Includes admin CRUD, standard seeding algorithm,
bye handling, and a CSS Grid bracket renderer on the frontend.

Add comprehensive tests for backend API/admin handlers, seeding logic,
and frontend bracket component.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

1 files changed, 16 insertions, 2 deletions

diff --git a/typespec/api-server/models.tsp b/typespec/api-server/models.tsp
index 47519be..6605767 100644
--- a/typespec/api-server/models.tsp
+++ b/typespec/api-server/models.tsp
@@ -106,14 +106,28 @@ model RankingEntry {
 }
 
 model Tournament {
+  tournament_id: integer;
+  display_name: string;
+  bracket_size: integer;
+  num_rounds: integer;
+  entries: TournamentEntry[];
   matches: TournamentMatch[];
 }
 
+model TournamentEntry {
+  user: User;
+  seed: integer;
+}
+
 model TournamentMatch {
-  game_id: integer;
+  tournament_match_id: integer;
+  round: integer;
+  position: integer;
+  game_id?: integer;
   player1?: User;
   player2?: User;
   player1_score?: integer;
   player2_score?: integer;
-  winner?: integer;
+  winner_user_id?: integer;
+  is_bye: boolean;
 }