feat(spa): sync host/player hash phase routes during gameplay

frontend/angular/src/app/features/host/host-shell.component.ts

@@ -147,6 +147,7 @@ export class HostShellComponent implements OnInit {
       if (this.session.session.status !== 'finished') {
         this.resetFinalLeaderboard();
       }
+      this.syncRouteFromSession();
     } catch (error) {
       this.error = `Session refresh failed: ${(error as Error).message}`;
     } finally {
@@ -166,6 +167,7 @@ export class HostShellComponent implements OnInit {
       this.roundQuestionId = this.session.round_question?.id ? String(this.session.round_question.id) : '';
       this.scoreboardPayload = '';
       this.resetFinalLeaderboard();
+      this.syncRouteFromSession();
     });
   }
 
@@ -263,6 +265,25 @@ export class HostShellComponent implements OnInit {
     this.finalWinner = null;
   }
 
+  private syncRouteFromSession(): void {
+    if (!this.session) {
+      return;
+    }
+
+    const phase = this.session.session.status || 'lobby';
+    const code = this.normalizeCode(this.session.session.code || this.sessionCode);
+    if (!code) {
+      return;
+    }
+
+    const targetPath = `#/host/${encodeURIComponent(phase)}/${encodeURIComponent(code)}`;
+    if (typeof window === 'undefined' || window.location.hash === targetPath) {
+      return;
+    }
+
+    window.history.replaceState(window.history.state, '', targetPath);
+  }
+
   private async runAction(action: () => Promise<void>): Promise<void> {
     this.loading = true;
     this.error = '';