Add 17 webhook provider skills (payments, dev, auth, scheduling, CRM)

[leggetter]

Summary

Adds webhook skills for 17 providers that fill genuine category gaps in the existing catalog, generated with the repo's own generator (generate-skills.sh) — each as an isolated claude sub-process that produced SKILL.md + references + Express/Next.js/FastAPI examples with tests, self-reviewed against the provider's official docs.

Category	Providers
Payments / billing	Square, Adyen, Razorpay, Mollie, GoCardless, Recurly, Coinbase Commerce
Dev / project management	Jira, Bitbucket
Auth / identity	Auth0, Okta, WorkOS
Meetings / scheduling	Zoom, Calendly
CRM / marketing	Salesforce, Mailchimp, Klaviyo

Each skill lands as its own feat: add <provider>-webhooks skill commit, preceded by one registry commit that adds all 17 entries to providers.yaml and the README Provider Skills table.

Notable auth handling

Several of these providers do not use a standard HMAC signature, and the skills teach the correct model rather than a generic pattern:

• Zoom — x-zm-signature HMAC over v0:{timestamp}:{body} plus the one-time endpoint.url_validation handshake (returns plainToken + hex encryptedToken), implemented and tested in all three frameworks.
• Salesforce — Outbound Messages (SOAP/XML): validate <OrganizationId> and return <Ack>true</Ack>; Platform Events / CDC noted as the streaming alternative.
• Mollie — webhooks are unsigned; teaches the fetch-to-confirm pattern (fetch the payment by id from the API rather than trusting the body).
• Auth0 — Custom Log Streams (batched JSON array) authenticated via a configured Authorization token.
• Okta — Event Hooks one-time verification challenge (X-Okta-Verification-Challenge) + Authorization-header secret.
• Mailchimp — unsigned; GET validation + unguessable URL secret.
• Adyen — additionalData.hmacSignature computed over selected fields; WorkOS / Calendly — Stripe-style t=…,v1=… HMAC with timestamp tolerance.

Validation

• ✅ Generator's generate → test → review loop passed for all 17 (0 blocking issues)
• ✅ scripts/validate-provider.sh passes for all 17 — required files, README table entry, and providers.yaml entry with testScenario
• ✅ Example tests (Express / Next.js / FastAPI) run during generation
• ✅ No node_modules committed; registry table kept alphabetized

providers.yaml now tracks 53 providers.

Not included

• Plaid was left out (treated as fintech data-aggregation rather than a payment processor) — easy to add on request.

🤖 Generated with Claude Code

https://claude.ai/code/session_01TkRuaGgYUz9q4k3yokqWKm

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Generated by Claude Code

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