Refactor large files into modular components

- Refactored page.tsx (613→252 lines) with GameOverScreen and LeftPanel extracted
- Refactored StatsTab.tsx (584→92 lines) with section components
- Refactored SkillsTab.tsx (434→54 lines) with sub-components
- Created modular structure for GameContext, LootInventory, and other components
- All extracted components organized into feature directories

src/lib/game/stores/gameActions.ts

@@ -0,0 +1,58 @@
+import { computeMaxMana } from '../utils';
+import { computeEffects } from '../upgrade-effects';
+import { useUIStore } from './uiStore';
+import { usePrestigeStore } from './prestigeStore';
+import { useManaStore } from './manaStore';
+import { useSkillStore } from './skillStore';
+import { useCombatStore } from './combatStore';
+
+export const createResetGame = (set: (state: any) => void, initialState: any) => () => {
+  // Clear all persisted state
+  localStorage.removeItem('mana-loop-ui-storage');
+  localStorage.removeItem('mana-loop-prestige-storage');
+  localStorage.removeItem('mana-loop-mana-storage');
+  localStorage.removeItem('mana-loop-skill-storage');
+  localStorage.removeItem('mana-loop-combat-storage');
+  localStorage.removeItem('mana-loop-game-storage');
+
+  const startFloor = 1;
+
+  useUIStore.getState().resetUI();
+  usePrestigeStore.getState().resetPrestige();
+  useManaStore.getState().resetMana({}, {}, {}, {});
+  useSkillStore.getState().resetSkills();
+  useCombatStore.getState().resetCombat(startFloor);
+
+  set({
+    ...initialState,
+    initialized: true,
+  });
+};
+
+export const createGatherMana = () => () => {
+  const skillState = useSkillStore.getState();
+  const manaState = useManaStore.getState();
+  const prestigeState = usePrestigeStore.getState();
+
+  // Compute click mana
+  let cm = 1 + 
+    (skillState.skills.manaTap || 0) * 1 + 
+    (skillState.skills.manaSurge || 0) * 3;
+
+  // Mana overflow bonus
+  const overflowBonus = 1 + (skillState.skills.manaOverflow || 0) * 0.25;
+  cm = Math.floor(cm * overflowBonus);
+
+  const effects = computeEffects(skillState.skillUpgrades || {}, skillState.skillTiers || {});
+  const max = computeMaxMana(
+    { 
+      skills: skillState.skills, 
+      prestigeUpgrades: prestigeState.prestigeUpgrades, 
+      skillUpgrades: skillState.skillUpgrades, 
+      skillTiers: skillState.skillTiers 
+    },
+    effects
+  );
+
+  useManaStore.getState().gatherMana(cm, max);
+};