Standardize loading states across all components

Replaced custom loading spinners with standardized LoadingState component from AsyncComponent.tsx. This ensures consistent UX for all data-loading operations.

Changes:
- web/src/components/staking/StakingDashboard.tsx: LoadingState for staking data
- web/src/components/governance/GovernanceOverview.tsx: LoadingState for governance data
- web/src/components/governance/ProposalsList.tsx: LoadingState for proposals
- web/src/components/dex/PoolBrowser.tsx: LoadingState for liquidity pools
- web/src/components/delegation/DelegationManager.tsx: LoadingState for delegation data
- web/src/components/forum/ForumOverview.tsx: LoadingState for forum threads
- web/src/components/treasury/TreasuryOverview.tsx: LoadingState for treasury data

All components now show:
- Kurdistan green animated spinner (Loader2)
- Contextual loading messages
- Consistent padding and centering
- Professional appearance

Button loading states (auth, wallet modals) left as-is since they appropriately disable during actions.

web/src/components/staking/StakingDashboard.tsx

@@ -21,6 +21,7 @@ import {
   parseAmount,
   type StakingInfo
 } from '@pezkuwi/lib/staking';
+import { LoadingState } from '@pezkuwi/components/AsyncComponent';
 
 export const StakingDashboard: React.FC = () => {
   const { t } = useTranslation();
@@ -421,11 +422,7 @@ export const StakingDashboard: React.FC = () => {
   };
 
   if (isLoadingData) {
-    return (
-      <div className="flex items-center justify-center h-64">
-        <div className="text-gray-400">Loading staking data...</div>
-      </div>
-    );
+    return <LoadingState message="Loading staking data..." />;
   }
 
   return (