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/governance/GovernanceOverview.tsx

@@ -9,6 +9,7 @@ import { Badge } from '../ui/badge';
 import { Progress } from '../ui/progress';
 import { usePolkadot } from '../../contexts/PolkadotContext';
 import { formatBalance } from '@pezkuwi/lib/wallet';
+import { LoadingState } from '@pezkuwi/components/AsyncComponent';
 
 interface GovernanceStats {
   activeProposals: number;
@@ -123,6 +124,10 @@ const GovernanceOverview: React.FC = () => {
     }
   };
 
+  if (loading) {
+    return <LoadingState message="Loading governance data..." />;
+  }
+
   return (
     <div className="space-y-6">
       {/* Stats Grid */}