fix(pact-system): resolve 5 spec-vs-code discrepancies (DISC-4,6,8,11,12)

- DISC-11: Fix floor 140/150 element composition in guardian-data.ts
  Floor 140 now uses [light, fire, radiantflames] (was [sand, earth, water])
  Floor 150 now uses [air, death, miasma] (was [lightning, fire, air])
- DISC-12: Reconcile spec §7.1 vs §8.2 tables in pact-system-spec.md
  Updated §8.2 to match §7.1 authoritative element mappings
- DISC-4: Deduplicate pact ritual completion logic
  Refactored pact-ritual.ts pipeline to delegate completion to
  prestigeStore.completePactRitual() instead of duplicating state writes
- DISC-6: Add 4 missing boon types to guardians
  critChance (floor 90), manaGain (floor 110), prestigeInsight (floor 200),
  studySpeed (floor 220) — all 12 spec boon types now used
- DISC-8: Add comment clarifying signedPactDetails persistence
  Code already correct (not reset by startNewLoop/resetPrestigeForNewLoop)
- Updated spire-utils.test.ts to match corrected floor 140/150 elements

docs/dependency-graph.json

@@ -1,6 +1,6 @@
 {
   "_meta": {
-    "generated": "2026-06-08T18:36:56.442Z",
+    "generated": "2026-06-08T20:08:31.411Z",
     "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."
   },
@@ -539,6 +539,7 @@
     ],
     "stores/attunementStore.ts": [
       "data/attunements.ts",
+      "stores/combatStore.ts",
       "types.ts",
       "utils/safe-persist.ts"
     ],