fix: unify guardian system references across pact-utils, SpireSummaryTab, PactDebug, and PactDebugSection

- pact-utils.ts: Replace GUARDIANS[floor] with getGuardianForFloor() so pact multipliers work for extended guardians (floors 110+)
- SpireSummaryTab.tsx: Use getGuardianForFloor()/getAllGuardianFloors() instead of static GUARDIANS constant; update type annotations to GuardianDef
- PactDebug.tsx: Use unified guardian lookup; add null guards for getGuardianForFloor return type
- PactDebugSection.tsx: Use unified guardian lookup; add null guards for getGuardianForFloor return type

docs/dependency-graph.json

@@ -1,6 +1,6 @@
 {
   "_meta": {
-    "generated": "2026-05-22T16:18:29.615Z",
+    "generated": "2026-05-23T11:46:20.479Z",
     "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."
   },
@@ -359,6 +359,7 @@
       "data/golems/types.ts"
     ],
     "data/guardian-encounters.ts": [
+      "constants/guardians.ts",
       "types.ts"
     ],
     "data/loot-drops.ts": [