Refactor state management for active tabs and optimize component rendering

- Introduced `activeTabStore` to manage active tab state with fine-grained subscriptions.
- Replaced direct prop passing of `isActive` with hooks (`useIsVaultActive`, `useIsSftpActive`) in components to determine active state.
- Memoized components (e.g., `SftpView`, `VaultView`, `TerminalLayer`, `TopTabs`) to prevent unnecessary re-renders.
- Updated various components to use `useCallback` and `useMemo` for stable references and performance improvements.
- Removed redundant state and props, simplifying the component structure.
- Disabled React.StrictMode in index.tsx for performance testing.

index.tsx

@@ -9,7 +9,8 @@ if (!rootElement) {
 
 const root = ReactDOM.createRoot(rootElement);
 root.render(
-  <React.StrictMode>
+  // StrictMode causes double renders in development - disabled for performance testing
+  // <React.StrictMode>
     <App />
-  </React.StrictMode>
+  // </React.StrictMode>
 );