feat(sdk): PTB composition support for all transaction methods

[jangid]

Summary

• All transaction-building SDK methods now accept an optional tx parameter that lets callers pass in an existing Transaction to append operations to
• Enables composing multiple AlphaFi operations into a single Programmable Transaction Block (PTB)
• Fully backward-compatible — omitting tx preserves existing behavior (creates a fresh transaction)

Motivation

Community request: bot developers and integrators need to compose multiple AlphaFi SDK calls (deposit, withdraw, claim, swap, etc.) into a single PTB for atomic execution, lower gas costs, and tighter integration with other Sui protocols.

Changes

src/core/types.ts — Added optional tx?: Transaction field to all options interfaces:

• DepositOptions, WithdrawOptions, ZapDepositOptions
• ClaimOptions, ClaimAirdropOptions
• ClaimWithdrawAlphaOptions, ClaimWithdrawSlushOptions (and CancelWithdrawSlushOptions via type alias)
• CetusSwapOptions

src/core/index.ts — Updated all methods to use options.tx ?? new Transaction():

• deposit, withdraw, initiateWithdrawAlpha
• claimWithdrawAlpha, claimWithdrawSlush, cancelWithdrawSlush
• claimAirdrop, claim
• cetusSwapTxb, zapDepositTxb
• vote, updatePool (positional existingTx? parameter)

Usage

// Before: each call creates its own transaction
const depositTx = await sdk.deposit({ poolId, address, amount: 100n });
const withdrawTx = await sdk.withdraw({ poolId: otherPool, address, amount: '50', withdrawMax: false });
// Two separate transactions to sign and execute

// After: compose into a single PTB
const tx = new Transaction();
await sdk.deposit({ tx, poolId, address, amount: 100n });
await sdk.withdraw({ tx, poolId: otherPool, address, amount: '50', withdrawMax: false });
// One atomic transaction to sign and execute
await client.signAndExecuteTransaction({ transaction: tx, signer });

Test plan

• npm run build — clean compilation (CJS + ESM)
• Pre-commit hooks pass (Prettier, ESLint, TypeScript type check, build check)
• Manual test: compose deposit + withdraw into single PTB and execute on testnet
• Verify omitting tx still works identically to current behavior