fix: address the final whole-branch review's findings

The branch review approved the slice with no blocking findings. These
are the substantive non-blocking ones.

N1, the one no per-task review could see: every seeded monster rolls
silverMin/silverMax = 0 (R7), so the victory screen showed "Silber +0"
after every fight in the shipped game. Three tasks were each correct in
isolation -- the mechanism stays, the values are zero, the field still
exists -- and the composite was wrong. Now conditional, with a test.
This does not contradict R16: R16 deleted the XP block because the
field ceased to exist, leaving nothing to hide. Silver still exists and
can be non-zero, so a conditional is the right tool.

N2: world.store.ts still said a combat "granted XP and silver". Same
false-fact-in-a-comment defect fixed in b5bcd50, one file over.

N4: resolveReputationRank threw a TypeError on negative input, since
findIndex returns -1 and REPUTATION_RANKS[-1] is undefined. Unreachable
today, but grantReputation is public and accepts any number.

N5/N6: grantReputation resolved factions without the enabled filter the
read path applies, so a disabled faction could accumulate invisible
reputation -- "disabled" was not actually a kill switch. The dense read
also had no ORDER BY, so the list could reorder between requests.

N8: design 13 requires silver stay 0 for every seeded monster; only two
of four were pinned. Re-adding silver to the others would have shipped
silently.

N9: spec 36's "a normal kill grants no Renown" had no test. It was
structurally guaranteed but unasserted -- now locked down against a
later slice wiring renown into combat.

N10: an impossible renown: 0 fixture, and RENOWN_MIN exported but never
used to clamp the floor.

API 268/268, web 230/230, API build zero errors.

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

apps/api/src/rewards/combat-reward.service.spec.ts

@@ -137,7 +137,7 @@ function combat(overrides: Partial<Combat> = {}): Combat {
 
 function createState(overrides: Partial<State> = {}): State {
   return {
-    characters: [{ id: CHARACTER_ID, silver: 3 } as Character],
+    characters: [{ id: CHARACTER_ID, silver: 3, renown: 4 } as Character],
     monsters: [
       {
         id: ASH_RAT_ID,
@@ -348,6 +348,20 @@ describe('CombatRewardService', () => {
     });
   });
 
+  it('grants no renown for a normal monster kill', async () => {
+    const state = createState();
+    const loot = fakeLoot({ itemDefinitionId: BANDIT_BLADE, quantity: 1 });
+    const subject = service(state, loot, fixedRandom(0));
+
+    await subject.grantVictoryRewards(fakeManager(state), combat());
+
+    // Renown comes from milestones only (spec §36). Killing things must never
+    // move it -- that is the whole point of replacing XP with Renown, so this
+    // asserts the prohibition rather than trusting that nothing wired it up.
+    expect(state.characters[0].renown).toBe(4);
+    expect(state.characters[0].silver).toBe(7);
+  });
+
   describe('idempotency', () => {
     it('grants once and returns the same persisted reward on a repeat call', async () => {
       const state = createState();