WebGPU-accelerated Stellar scanner (research spike)

[truthixify]

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

Context

View-tag batching (#45 previous wave) gave us 229x speedup. WebGPU compute shaders could potentially push further by parallelizing ECDH across thousands of announcements at once. Spike to find out.

Scope

• Prototype WebGPU shader for X25519 scalar multiplication
• Benchmark vs. current optimized scan on 100k-announcement dataset
• Document feasibility, gotchas, and recommended path
• If win > 5x: file follow-up to land properly
• If not: document why and close

Acceptance criteria

• Working prototype (can be branch-only)
• Benchmark numbers
• Recommendation doc
• Either follow-up issue or clear "defer" rationale

Files to start with

• src/chains/stellar/scan.ts
• WebGPU compute shader docs

[maztah1]

@maztah1 has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

I would love to work on this issue please

ℹ️ Repo Maintainers: To accept this application, review their application or assign @maztah1 to this issue.

[drips-wave]

Congratulations, @maztah1! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on June 30, 2026.

🧑‍💻 @maztah1: Please resolve the issue such that the repo's maintainers have enough time to review your contribution before the due date. You'll earn Points for completing the issue on-time, which will make you eligible for a share of the Stellar Wave Program's reward pool.

Warning

When opening a PR, please link it to this issue to ensure it gets tracked accurately. Points are awarded when this issue is marked as completed by the maintainer.

🤠 Repo maintainers: Please keep an eye on the contributor's progress and review their work before the due date. You can manage this issue, including adjusting its complexity and points, here.

🌊 Happy Wave 🌊

[truthixify]

@maztah1 Assigned. Welcome to wave 6.

Quick expectations:

1. Branch from develop (not main). PRs target develop. (Note: I just changed the GitHub default to develop so it should auto-pick now.)
2. Open a draft PR within ~3 days of pickup so we can see direction.
3. Update at least every 5 days. Silence is the only thing that costs you the assignment.
4. Hit the acceptance criteria in the issue body. That's the merge bar.

If anything is ambiguous, ask on the issue before building.