feat(combat): add CombatPageComponent and replace the combat/new placeholder route

Wires up the Slice 0.3 combat screen (player/monster HP bars, round
display, Angriff action, grouped German combat log, victory/defeat
panels) and replaces the Slice 0.2 combat/new placeholder route with
combat/:combatId loading CombatPageComponent.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

apps/web/src/app/app.routes.ts

@@ -22,10 +22,10 @@ export const routes: Routes = [
           ),
       },
       {
-        path: 'combat/new',
+        path: 'combat/:combatId',
         loadComponent: () =>
-          import('./features/combat/combat-placeholder-page.component').then(
-            (module) => module.CombatPlaceholderPageComponent,
+          import('./features/combat/combat-page/combat-page.component').then(
+            (module) => module.CombatPageComponent,
           ),
       },
     ],