Restore global landing page, mega-nav, and CCIP landing page

This commit restores three key components that were previously reverted:

1. Global landing page (/) - Restore the redesigned homepage with
   ProductTabs and enhanced layout from feat/dev-3.0

2. Global header with Docs mega-nav - Restore the updated navigation
   header with mega menu for Resources/Docs navigation including:
   - Desktop MegaMenu with product categories
   - Mobile responsive navigation
   - Updated ProductNavigation components

3. CCIP landing page (/ccip) - Restore the CCIP landing page content
   from feat/dev-3.0 branch

These changes align feat/dev-3.0-no-landing with the enhanced UX
from feat/dev-3.0 while maintaining the "no-landing" architecture.

Author: markshenouda

src/components/CCIP/TutorialBlockchainSelector/TutorialBlockchainSelector.tsx

@@ -32,9 +32,9 @@ export const TutorialBlockchainSelector = () => {
     const currentState = laneStore.get()
     const bothChainsSelected = Boolean(
       currentState.sourceChain &&
-      currentState.destinationChain &&
-      currentState.sourceNetwork &&
-      currentState.destinationNetwork
+        currentState.destinationChain &&
+        currentState.sourceNetwork &&
+        currentState.destinationNetwork
     )
     updateStepProgress("setup", "blockchains-selected", bothChainsSelected)
   }