Install Stellar SDK

[Fidelis900]

Title: Add Stellar SDK Dependencies
Labels: frontend, setup, stellar
Priority: Critical
Estimated Time: 30 minutes

Description:
Install and configure Stellar SDK for frontend.

Tasks:

• Install @stellar/stellar-sdk
• Install @stellar/freighter-api (wallet)
• Install stellar-sdk types
• Create SDK configuration file
• Set up network configuration (testnet/mainnet)

Acceptance Criteria:

• SDK imports work
• Network configuration correct
• Wallet connection possible

---