Stellar Liquidity Pool swap-then-stealth helper

[truthixify]

Tier: L (1-2 weeks) Type: feature

Context

Sender holds USDC, recipient prefers XLM. Use Stellar AMM to swap then send to stealth address, all atomically. Helper builds this combined transaction.

Scope

• buildStellarSwapAndStealth({ fromAsset, toAsset, amount, recipientMeta }) returns single transaction
• Uses pathPaymentStrictReceive or liquidityPoolDeposit/Withdraw as appropriate
• Slippage protection (configurable)
• Stealth address still receives the announcement
• Tests against testnet AMM

Acceptance criteria

• Helper + tests
• Slippage protection documented
• Integration test with testnet pools
• Documentation page with worked example

Files to start with

• New: sdk/src/chains/stellar/swap.ts