feat: Add Miden logo and update references

- Added miden-logo.png to public folder
- Updated PrivacyBridgeForm to use local Miden logo
- Updated providerMeta to use local Miden logo
- Replaced placeholder Polygon logo with actual Miden logo

Author: maxgershfield

zypherpunk-wallet-ui/components/bridge/PrivacyBridgeForm.tsx

@@ -38,7 +38,7 @@ export const privacyBridgeChains = [
   { 
     name: 'Miden', 
     symbol: 'MIDEN', 
-    logoUrl: 'https://polygon.technology/logo.svg', // Using Polygon logo as placeholder until Miden logo is available
+    logoUrl: '/miden-logo.png',
     network: 'Miden',
     description: 'Zero-knowledge VM for privacy',
     providerType: ProviderType.MidenOASIS,

zypherpunk-wallet-ui/lib/providerMeta.ts

@@ -50,7 +50,7 @@ export const providerMetadataMap: Partial<Record<ProviderType, ProviderMetadata>
     description: 'Zero-knowledge VM for privacy-preserving applications',
     accentColor: '#8b5cf6',
     backgroundGradient: 'from-[#8b5cf6] to-[#7c3aed]',
-    logoUrl: 'https://polygon.technology/logo.svg', // TODO: Add proper Miden logo
+    logoUrl: '/miden-logo.png',
     category: 'Layer2',
   },
   [ProviderType.EthereumOASIS]: {