Pull request overview

This PR hardens the Anchor transfer_sol_with_program example to prevent unauthorized lamport drains by requiring the source (payer) to sign and by using checked lamport arithmetic with explicit error reporting.

Changes:

• Require payer to be a Signer<'info> (while still enforcing owner = id()).
• Add explicit insufficient-funds check plus checked sub/add for lamport math, returning custom errors.
• Update the Anchor TS test to include payerAccount as an explicit signer.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
basics/transfer-sol/anchor/programs/transfer-sol/src/lib.rs	Enforces payer signature + checked lamport mutation with custom error codes.
basics/transfer-sol/anchor/tests/test.ts	Updates the “Transfer SOL with Program” test to sign with the program-owned payer keypair.

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