refactor: resolve structural inconsistencies and dead code

- Fix broken barrel exports in components/game/index.ts
- Remove skill system from stores (gameStore, gameActions, gameLoopActions, gameHooks, craftingStore, combat)
- Remove skill system from components (page.tsx, LeftPanel, StatsTab, SpellsTab, EnchantmentDesigner, EnchantmentPreparer, GameContext/Provider)
- Delete dead code: stats/ directory, attunements/ directory, layout/ Header+TabBar, shared/ StudyProgress+UpgradeDialog duplicates, effects.ts.fix, study-slice.ts, navigation-slice.ts
- Delete legacy store/ and store-modules/ directories, redirect remaining callers
- Merge root formatting.ts into utils/formatting.ts
- Move effects files (dynamic-compute, upgrade-effects, special-effects, upgrade-effects.types) into effects/ directory
- Move debug-context.tsx into components/game/debug/
- Create tabs/index.ts barrel for tab components
- Fix page.tsx lazy imports to use tabs barrel
- Fix all broken import paths across codebase
- Remove SKILLS_DEF and skill-evolution references
- Trim store.ts to under 400 lines by removing dead skill actions

src/components/game/debug/debug-context.tsx

@@ -0,0 +1,69 @@
+'use client';
+
+import { createContext, useContext, useState, useEffect, type ReactNode } from 'react';
+
+interface DebugContextType {
+  showComponentNames: boolean;
+  toggleComponentNames: () => void;
+}
+
+const DebugContext = createContext<DebugContextType | null>(null);
+
+export function DebugProvider({ children }: { children: ReactNode }) {
+  // Initialize from localStorage if available
+  const [showComponentNames, setShowComponentNames] = useState(() => {
+    if (typeof window !== 'undefined') {
+      const saved = localStorage.getItem('debug-show-component-names');
+      return saved === 'true';
+    }
+    return false;
+  });
+
+  const toggleComponentNames = () => {
+    setShowComponentNames(prev => {
+      const newValue = !prev;
+      localStorage.setItem('debug-show-component-names', String(newValue));
+      return newValue;
+    });
+  };
+
+  return (
+    <DebugContext.Provider value={{ showComponentNames, toggleComponentNames }}>
+      {children}
+    </DebugContext.Provider>
+  );
+}
+
+export function useDebug() {
+  const context = useContext(DebugContext);
+  if (!context) {
+    // Return default values if used outside provider
+    return { showComponentNames: false, toggleComponentNames: () => {} };
+  }
+  return context;
+}
+
+// Wrapper component to show component name in debug mode
+interface DebugNameProps {
+  name: string;
+  children: ReactNode;
+}
+
+export function DebugName({ name, children }: DebugNameProps) {
+  const { showComponentNames } = useDebug();
+
+  if (!showComponentNames) {
+    return <>{children}</>;
+  }
+
+  return (
+    <div className="relative">
+      <div className="absolute -top-5 left-0 text-[10px] font-mono text-yellow-400 bg-yellow-900/50 px-1 rounded z-50">
+        {name}
+      </div>
+      {children}
+    </div>
+  );
+}
+
+DebugName.displayName = "DebugName";