Fix webhook JSON example and add visible signup labels

[marcosgcuenta1]

The webhook Body example used | null unions that made it invalid JSON. Use concrete values in the example and explain nullable fields separately. Add persistent Email and Password labels associated with the signup inputs.

Validation: JSON.parse and source checks for visible label/input associations pass (all failed before the change); git diff --check and tsc --noEmit pass. Installed dependencies with Bun 1.4.2 using the frozen lockfile and disabled install scripts/browser downloads. Full vitest run: 2743 passed, 18 failed, 9 skipped. All 18 failures also reproduce in the unchanged base commit across the same 9 files (ffmpeg availability and environment-sensitive behavior on Windows). No dependency or lockfile changes. Browser rendering was not exercised.

Implemented with AI assistance; no authenticated flows were exercised.

I found these while reviewing the four public pages (landing, pricing, signup, and webhook docs) for the CrawlProof $2 feedback offer. Does this public report/PR qualify, or is submission through ugig required? No reward approval is assumed. Regarding “Would you pay for this?”: not for our current project; we do not currently need recurring site audits, and only public flows were evaluated.

[marcosgcuenta1]

Thanks for merging! Does this report and fix qualify for your $2 CrawlProof feedback bounty?

Update: I submitted the work to the ugig bounty as tinyfeedbackstudio. If approved, can the reward be paid through the existing Lightning wallet on that account, or is SOL the only supported payout option?