fix: handle undefined state/obj in mana calculations to prevent runtime error

src/components/game/StatsTab/ManaStatsSection.tsx

@@ -56,7 +56,7 @@ export function ManaStatsSection({
                 {(() => {
                   const mw = skillTiers?.manaWell || 1;
                   const tieredSkillId = mw > 1 ? `manaWell_t${mw}` : 'manaWell';
-                  const level = skills[tieredSkillId] || skills.manaWell || 0;
+                  const level = (skills || {})[tieredSkillId] || (skills || {}).manaWell || 0;
                   const tierMult = getTierMultiplier(tieredSkillId);
                   return `+${fmt(level * 100 * tierMult)} (${level} lvl × 100 × ${tierMult}x tier)`;
                 })()}

src/lib/game/store-modules/computed-stats.ts

@@ -29,7 +29,7 @@ export function computeMaxMana(
 ): number {
   const pu = state.prestigeUpgrades;
   const skillMult = (effects as any)?.skillLevelMultiplier || 1;
-  const base = 100 + (state.skills.manaWell || 0) * 100 * skillMult + (pu.manaWell || 0) * 500;
+  const base = 100 + ((state.skills || {}).manaWell || 0) * 100 * skillMult + ((pu || {}).manaWell || 0) * 500;
   
   // Check if we need to compute effects from equipment
   if (!effects && state.equipmentInstances && state.equippedInstances) {

src/lib/game/store/computed.ts

@@ -34,7 +34,7 @@ export function computeMaxMana(
   const base =
     100 +
     manaWellLevel.level * 100 * manaWellLevel.tierMultiplier +
-    (pu.manaWell || 0) * 500;
+    ((pu || {}).manaWell || 0) * 500;
 
   const computedEffects = effects ?? computeEffects(skillUpgrades, skillTiers);
   // Apply MANA_HEART bonus (+10% per loop, compounds)

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

@@ -12,8 +12,8 @@ export function computeMaxMana(
   const pu = state.prestigeUpgrades;
   const base = 
     100 +
-    (state.skills.manaWell || 0) * 100 +
+    ((state.skills || {}).manaWell || 0) * 100 +
-    (pu.manaWell || 0) * 500;
+    ((pu || {}).manaWell || 0) * 500;
   
   // Apply upgrade effects if provided
   if (effects) {
@@ -34,9 +34,9 @@ export function computeRegen(
   const temporalBonus = 1 + (pu.temporalEcho || 0) * 0.1;
   const base =
     2 +
-    (state.skills.manaFlow || 0) * 1 +
+    ((state.skills || {}).manaFlow || 0) * 1 +
-    (state.skills.manaSpring || 0) * 2 +
+    ((state.skills || {}).manaSpring || 0) * 2 +
-    (pu.manaFlow || 0) * 0.5;
+    ((pu || {}).manaFlow || 0) * 0.5;
   
   let regen = base * temporalBonus;
   
@@ -90,8 +90,8 @@ export function computeEffectiveRegen(
 export function computeClickMana(state: Pick<GameState, 'skills'>): number {
   return (
     1 +
-    (state.skills.manaTap || 0) * 1 +
+    ((state.skills || {}).manaTap || 0) * 1 +
-    (state.skills.manaSurge || 0) * 3
+    ((state.skills || {}).manaSurge || 0) * 3
   );
 }