[Web] User dashboard — manage linked addresses, memo ID, and vault overview

[ryzen-xp]

📝 Description

Build the authenticated user dashboard for registered username owners. After connecting their wallet, users can manage their Alien Gateway identity: add/remove Stellar and external chain addresses, set a Stellar memo ID, and view their escrow vault balance and scheduled payments.

✅ Requirements

• Auth: wallet-gated — redirect to connect wallet if not connected
• Show registered @username with ownership confirmation
• Linked Stellar addresses list: add, set as primary, remove
• External chain addresses (EVM, BTC, Solana): add and remove
• Memo ID: set and update
• Vault section: deposit balance, pending scheduled payments, trigger execute_scheduled
• All mutations call the relevant contract functions via SDK
• Optimistic UI with transaction confirmation toasts

🎯 Acceptance Criteria

• Dashboard only accessible to wallet that owns the username
• All address operations call the correct contract entry points
• Vault balance displayed correctly
• Scheduled payments list shows release time and amount
• execute_scheduled button appears when release time has passed
• Error handling for failed transactions

📁 Expected files to change/structure

• src/pages/dashboard.tsx
• src/components/AddressManager.tsx
• src/components/VaultPanel.tsx
• src/components/ScheduledPayments.tsx
• src/hooks/useDashboard.ts

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🌿 Branch: feat/web-dashboard | Priority: HIGH | Difficulty: ☕☕☕ all-nighter