fix: show finished games on watch page instead of hanging spinner (#16)

Summary
▎
▎ - Opening a finished game caused an infinite spinner because the NDJSON stream never delivers events for finished games — it just hangs waiting for events that will never come
▎ - Fix: fetch the full game state via REST on load (GET .../game/{gameId}), apply it to the board immediately, and only open the stream subscription if the game is still ongoing or pending
▎
▎ Changes
▎
▎ - tournament-watch.component.ts — REST fetch now drives the initial state; stream is only started conditionally; extracted applySnapshot(), isFinished(), subscribeToStream()
▎
▎ Test plan
▎
▎ - [ ] Finished game: board shows final position, correct status label, no spinner
▎ - [ ] Live game: board shows current position, stream updates continue to work
▎ - [ ] Pending game: stream starts and updates once the game begins

---------

Co-authored-by: LQ63 <lkhermann@web.de>
Reviewed-on: #16

src/app/pages/tournament-watch/tournament-watch.component.ts

@@ -59,19 +59,43 @@ export class TournamentWatchComponent implements OnInit {
       .pipe(takeUntilDestroyed(this.destroyRef))
       .subscribe({
         next: game => {
-          this.whiteName = game.white?.name ?? null;
-          this.blackName = game.black?.name ?? null;
+          this.applySnapshot(game);
+          this.connecting = false;
+          if (!this.isFinished(game.status)) {
+            this.subscribeToStream();
+          }
+        },
+        error: err => {
+          this.connecting = false;
+          this.error = (err as Error).message ?? 'Failed to load game.';
         },
       });
+  }
 
+  private applySnapshot(game: GameStateSnapshot): void {
+    this.whiteName = game.white?.name ?? null;
+    this.blackName = game.black?.name ?? null;
+    this.snapshot = game;
+    this.fen = game.fen;
+    this.turn = game.turn;
+    this.status = game.status;
+    this.winner = game.winner;
+    this.clock = game.clock ?? null;
+    this.moves = game.moves ? game.moves.split(/\s+/).filter(Boolean) : [];
+  }
+
+  private isFinished(status: GameStatus): boolean {
+    return status !== 'pending' && status !== 'ongoing';
+  }
+
+  private subscribeToStream(): void {
     this.stream.streamGame(this.serverUrl, this.tournamentId, this.gameId)
       .pipe(takeUntilDestroyed(this.destroyRef))
       .subscribe({
         next: ev => this.apply(ev),
         error: err => {
-          this.connecting = false;
           this.error = (err as Error).message ?? 'Stream failed.';
-        }
+        },
       });
   }