Testing: Expand fuzzing for merkle proofs, XDR decoding, and webhook payloads

[joelpeace48-cell]

Context

Untrusted inputs (merkle proofs in register, XDR/event decoding, inbound webhook bodies) are prime
fuzz targets and likely under-fuzzed.

Scope

• cargo-fuzz targets for proof verification and any custom decoding.
• JS fuzzing for webhook/payload parsers and input validators.
• Corpus + CI fuzz smoke run; longer scheduled fuzz job.

Acceptance criteria

• Fuzz targets exist for each untrusted parser; CI runs a smoke fuzz; crashes block merge.

Verification

• A seeded panic on malformed proof/payload is caught by the fuzzer.

[spiffamani]

I'm a full-stack Software Engineer
I'd love to take this on — thanks for considering me

[spiffamani]

I'm a full-stack Software Engineer
I'd love to take this on — thanks for considering me

[gloskull]

Hello, I have 4 years of experience delivering solutions for projects like this, covering backend, frontend, and smart contract development. After carefully reviewing your requirements, I have a clear understanding of the task and am confident in my ability to deliver a clean, efficient, and thoroughly tested solution on time. I prioritize code quality, maintainability, and industry best practices throughout the development process. My PR will be submitted in under 10hours.