[Bismithblde]

Linked issue

Fixes #790

What and why

A fundraiser target above u64::MAX / 10 is accepted at initialization, but even a one-token contribution panics when calculating target * 10 / 100 in u64.

Calculate the contribution limit once in u128 and reuse it for both contribution checks. Widen the cumulative comparison as well. The existing 10% cap and rounding are preserved. Update the README's embedded implementation.

Testing

• Both existing fundraiser integration tests passed before the change.
• Added a LiteSVM regression which failed against the original SBF program with attempt to multiply with overflow.
• The regression tests u64::MAX / 10 + 1 and u64::MAX, small contributions, the exact cumulative cap, over-limit rejections, token balances and recorded totals.
• Rebuilt using NO_DNA=1 cargo build-sbf --manifest-path programs/fundraiser/Cargo.toml --sbf-out-dir target/deploy --tools-version v1.57 --arch v3.
• cargo test with the shared local target directory passed all three fundraiser integration tests.
• git diff --check passed.

AI disclosure

• No AI tooling was used beyond editor autocomplete.
• AI tooling was used. Tool and extent: OpenAI Codex investigated and reproduced the overflow, wrote the fix, regression test and README update, and ran the listed checks.

[github-actions]

Hi @Bismithblde,

Thanks for the pull request. We ask that every change references an issue a maintainer has accepted, and there isn't one linked here.

These examples are a teaching resource and each one has to stay small enough to read in one sitting, so whether a new example or framework flavor belongs here is worth settling before anyone writes it. Agreeing on the approach in an issue first means nobody writes code that can't be merged. See CONTRIBUTING.md for the full workflow.

Please open an issue describing the change, or comment on the existing one. Once a maintainer has labelled it accepted, put Fixes #<issue> in this description and reopen this pull request; the check runs again and clears itself. Typos, broken links and comment-only fixes are exempt: write Linked issue: trivial instead.