refactor: complete error handling standardization (issue #101)

Prestige Store:
- Convert doPrestige() to return Result<void> with specific error codes
  (INVALID_PRESTIGE_ID, PRESTIGE_MAX_LEVEL, INSUFFICIENT_INSIGHT)
- Convert startPactRitual() to return Result<void> with specific error codes
  (GUARDIAN_NOT_DEFEATED, PACT_ALREADY_SIGNED, PACT_SLOTS_FULL,
   INSUFFICIENT_MANA, RITUAL_IN_PROGRESS)

Combat Actions:
- Add try/catch wrapper inside processCombatTick with safe fallback defaults
- Add makeDefaultCombatTickResult helper for error recovery

LocalStorage Error Handling:
- Create safe-persist.ts utility wrapping localStorage with error handling
  (corrupted JSON, quota exceeded, unexpected failures)
- Update all 8 Zustand stores to use createSafeStorage() in persist middleware

UI Updates:
- Update GuardianPactsTab to use Result pattern for ritual error messages

Tests:
- Update store-actions-combat-prestige.test.ts for Result return types
- Update store-actions.test.ts ManaStore tests for Result pattern
- Remove duplicate Prestige/Discipline sections from store-actions.test.ts
- All files under 400 line limit

601 tests pass (3 pre-existing failures in spire-utils.test.ts)

docs/circular-deps.txt

@@ -1,8 +1,8 @@
 # Circular Dependencies
-Generated: 2026-05-20T17:48:45.265Z
+Generated: 2026-05-20T19:05:27.642Z
 Found: 4 circular chain(s) — these MUST be fixed before modifying involved files.
 
-1. Processed 126 files (1.4s) (3 warnings)
+1. Processed 126 files (1.3s) (3 warnings)
 2. 1) stores/gameStore.ts > stores/gameActions.ts
 3. 2) stores/gameStore.ts > stores/gameLoopActions.ts
 4. 3) stores/gameStore.ts > stores/tick-pipeline.ts

docs/dependency-graph.json

@@ -1,6 +1,6 @@
 {
   "_meta": {
-    "generated": "2026-05-20T17:48:43.703Z",
+    "generated": "2026-05-20T19:05:26.102Z",
     "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."
   },
@@ -85,14 +85,16 @@
     ],
     "crafting-actions/application-actions.ts": [
       "crafting-apply.ts",
+      "stores/craftingStore.types.ts",
       "types.ts"
     ],
     "crafting-actions/computed-getters.ts": [
       "data/enchantment-effects.ts",
-      "types.ts"
+      "stores/craftingStore.types.ts"
     ],
     "crafting-actions/crafting-equipment-actions.ts": [
       "crafting-equipment.ts",
+      "stores/craftingStore.types.ts",
       "types.ts"
     ],
     "crafting-actions/design-actions.ts": [
@@ -100,13 +102,15 @@
       "crafting-utils.ts",
       "effects/special-effects.ts",
       "effects/upgrade-effects.ts",
+      "stores/craftingStore.types.ts",
       "types.ts"
     ],
     "crafting-actions/disenchant-actions.ts": [
-      "types.ts"
+      "stores/craftingStore.types.ts"
     ],
     "crafting-actions/equipment-actions.ts": [
       "crafting-utils.ts",
+      "stores/craftingStore.types.ts",
       "types.ts"
     ],
     "crafting-actions/index.ts": [
@@ -534,6 +538,7 @@
       "types/attunements.ts",
       "types/elements.ts",
       "types/equipment.ts",
+      "types/equipmentSlot.ts",
       "types/game.ts",
       "types/spells.ts"
     ],

docs/project-structure.txt

@@ -334,7 +334,9 @@ Mana-Loop/
 │       │   │   ├── index.ts
 │       │   │   ├── mana-utils.ts
 │       │   │   ├── pact-utils.ts
+│       │   │   ├── result.ts
 │       │   │   ├── room-utils.ts
+│       │   │   ├── safe-persist.ts
 │       │   │   └── spire-utils.ts
 │       │   ├── constants.ts
 │       │   ├── crafting-apply.ts