Verify wallet signature and authenticate

Verify a wallet signature and authenticate the user. This endpoint:
1. Validates the signature against the nonce
2. Creates or retrieves the user account
3. Issues JWT tokens (stored in HttpOnly cookies)
4. Returns user information and tokens

**Authentication Flow:**
1. Call `GET /api/v1/wallet/nonce/{address}/` to get a nonce
2. Sign the returned message with the user's wallet
3. Call this endpoint with the address, signature, and nonce
4. Receive JWT tokens in cookies and user data

**Token Storage:**
Tokens are stored in HttpOnly cookies for security. The access token is valid for 7 days, and the refresh token is valid for 1 day.