fix: correct API issues found by codex review across 10 CLIs

Fixes found by automated codex review of all 47 CLI tools:

- resend: webhook field name endpoint_url -> endpoint
- mailchimp: change from Bearer to Basic auth per API docs
- kit: fail fast when api_secret required but not set
- activecampaign: automation add-contact needs --contact-id not --email
- google-ads: budget updateMask must be snake_case (amount_micros)
- meta-ads: special_ad_categories default to ['NONE'] not empty array
- linkedin-ads: add required X-RestLi-Protocol-Version header
- onesignal: auth prefix should be Key, not Basic
- mixpanel: query dates must be YYYY-MM-DD, not relative strings
- wistia: change from Bearer to Basic auth per API docs

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

tools/clis/resend.js

@@ -203,7 +203,7 @@ async function main() {
           break
         case 'create': {
           const events = args.events?.split(',') || ['email.sent', 'email.delivered', 'email.bounced']
-          result = await api('POST', '/webhooks', { endpoint_url: args.endpoint, events })
+          result = await api('POST', '/webhooks', { endpoint: args.endpoint, events })
           break
         }
         case 'delete':