refactor: remove GUARDIANS constant, consolidate into guardian-data.ts

- Delete src/lib/game/constants/guardians.ts (the old static GUARDIANS constant)
- Create src/lib/game/data/guardian-data.ts with BASE_GUARDIANS (same data, new home)
- Remove GUARDIANS export from constants/index.ts
- Update all 11 files that imported GUARDIANS to use getGuardianForFloor() or BASE_GUARDIANS:
  - useGameDerived.ts, combat-actions.ts, gameStore.ts, prestigeStore.ts
  - combat-utils.ts, room-utils.ts, floor-utils.ts, spire-utils.ts
  - SpireCombatPage.tsx, SpireHeader.tsx
- Update 4 test files to use getGuardianForFloor() instead of GUARDIANS constant
- guardian-encounters.ts now imports BASE_GUARDIANS from guardian-data.ts
- Split room-utils.test.ts (505 lines) into room-utils.test.ts + room-utils-floor-state.test.ts

src/lib/game/utils/combat-utils.ts

@@ -2,8 +2,10 @@
 
 import type { SpellCost, EquipmentInstance } from '../types';
 import type { DisciplineBonuses } from './mana-utils';
-import { GUARDIANS, SPELLS_DEF, ELEMENT_OPPOSITES, INCURSION_START_DAY, MAX_DAY } from '../constants';
+import { SPELLS_DEF, ELEMENT_OPPOSITES, INCURSION_START_DAY, MAX_DAY } from '../constants';
 import { ENCHANTMENT_EFFECTS } from '../data/enchantment-effects';
+import { getGuardianForFloor } from '../data/guardian-encounters';
+import { BASE_GUARDIANS } from '../data/guardian-data';
 
 // ─── Damage Calculation Params ──────────────────────────────────────────────
 
@@ -86,7 +88,7 @@ export function getBoonBonuses(signedPacts: number[]): BoonBonuses {
   };
 
   for (const floor of signedPacts) {
-    const guardian = GUARDIANS[floor];
+    const guardian = getGuardianForFloor(floor);
     if (!guardian) continue;
 
     for (const boon of guardian.boons) {
@@ -158,7 +160,7 @@ export function calcDamage(
   const elemMasteryBonus = 1 + (skills.elementalMastery || 0) * 0.15;
 
   // Guardian bane bonus
-  const isGuardianFloor = floorElem && Object.values(GUARDIANS).some(g => g.element === floorElem);
+  const isGuardianFloor = floorElem && Object.values(BASE_GUARDIANS).some(g => g.element === floorElem);
   const guardianBonus = isGuardianFloor
     ? 1 + (skills.guardianBane || 0) * 0.2
     : 1;