fix(web): finish the reward-preview sweep the seed change started

When I dropped Silber and Erfahrung from the burned road's seeded
reward preview (e5752c7, because R7 zeroed every monster's silver on
that road), I updated the server content but not the web fixture that
mirrors it. burnedRoadFixture() still advertised Silber, and the
sidebar spec still asserted it rendered -- so the web tests were
proving the UI shows a category the API no longer sends.

Also clears dead level/experience fixture fields and an experience key
in a reward-service mock from combat-equipment-integration.spec.ts.
They were inert (nothing read them) but they date from after the
API-side sweep and describe fields the entity and DTO no longer have.

API 267/267, web 229/229.

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

apps/api/src/combat/combat-equipment-integration.spec.ts

@@ -190,8 +190,6 @@ function character(overrides: Partial<Character> = {}): Character {
   return {
     id: CHARACTER_ID,
     name: 'Aric Duskwalker',
-    level: 1,
-    experience: 0,
     silver: 0,
     baseHp: 100,
     baseAttack: 6,
@@ -283,7 +281,7 @@ function fakeRewardService(): CombatRewardService {
   return {
     grantVictoryRewards: jest
       .fn()
-      .mockResolvedValue({ experience: 0, silver: 0, items: [] }),
+      .mockResolvedValue({ silver: 0, items: [] }),
     loadRewards: jest.fn().mockResolvedValue(null),
   } as unknown as CombatRewardService;
 }