feat: add Safe wallet limit order example

[TetrisIsCute]

Summary

• Add a new Safe wallet example script examples/safeWallet/placeLimitOrder.ts.
• Demonstrate building a limit order and submitting it via a Safe transaction using the existing helpers and constants.
  Notes
• Example is configuration-only: users must provide their own RPC URL, private key, Safe address, and market token id in .env/script.
• No changes to shared library code or existing examples.

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Note

Adds a runnable Safe wallet example for placing a limit order.

• New examples/safeWallet/placeLimitOrder.ts builds a limit order with buildLimitOrder and executes it via signAndExecuteSafeTransaction
• Uses EXCHANGE_PROXY_ADDRESS, CHAIN_ID, and CLOB_API_URL; constructs SafeTransaction with order calldata
• Requires user-provided env/config: RPC_URL, PK, safeAddress, and marketTokenId

^{Written by Cursor Bugbot for commit 4f24f21. This will update automatically on new commits. Configure here.}

[cursor]

Wrong function signature for signAndExecuteSafeTransaction call

The signAndExecuteSafeTransaction function is called with an object argument, but the actual function in src/safe-helpers/index.ts expects positional arguments: (signer: Wallet, safe: Contract, txn: SafeTransaction, overrides?). All other examples in the codebase correctly call it as signAndExecuteSafeTransaction(wallet, safe, safeTxn, {gasPrice: ...}). The new code is missing the signer/wallet argument entirely and incorrectly passes an object with non-existent properties like apiUrl. This will cause the script to fail at runtime.