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

docs/dependency-graph.json

@@ -1,6 +1,6 @@
 {
   "_meta": {
-    "generated": "2026-05-23T11:46:20.479Z",
+    "generated": "2026-05-23T12:53:15.385Z",
     "description": "Import dependency graph for src/lib/game. Keys are files, values are arrays of files they import.",
     "usage": "To find what a file affects, search for its path in the VALUES. To find what a file depends on, look at its KEY entry."
   },
@@ -628,7 +628,7 @@
       "types.ts"
     ],
     "utils/pact-utils.ts": [
-      "constants.ts"
+      "data/guardian-encounters.ts"
     ],
     "utils/result.ts": [],
     "utils/room-utils.ts": [