fix: add input validation and safe JSON parsing across 13 CLIs

Add missing parameter validation to prevent /path/undefined API calls:
- dub: require --url for links create
- google-search-console: require --sitemap-url for sitemaps submit
- kit: validate IDs and emails for subscribers, forms, sequences, tags, broadcasts
- mailchimp: validate IDs for lists get, campaigns get/create/send, members add, reports get
- resend: validate --from/--to/--subject for send, audience/contact IDs for contacts
- rewardful: validate IDs for affiliates get/update, commissions get, links create
- semrush: require --domain/--phrase for all domain and keyword commands
- sendgrid: validate --from/--to/--subject for send, campaign IDs, email for validate

Wrap bare JSON.parse() calls in try/catch for user-provided JSON:
- dub (--links), ga4 (--params), kit (--fields x4), mixpanel (--properties x2),
  onesignal (--filters), paddle (--scheduled-change, --items x2),
  resend (--emails, --variables x2), segment (--properties, --traits, --events),
  sendgrid (--template-data)

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

tools/clis/google-search-console.js

@@ -129,6 +129,7 @@ async function main() {
           result = await api('GET', `/webmasters/v3/sites/${encodedSiteUrl}/sitemaps`)
           break
         case 'submit': {
+          if (!args['sitemap-url']) { result = { error: '--sitemap-url required' }; break }
           const sitemapUrl = encodeURIComponent(args['sitemap-url'])
           result = await api('PUT', `/webmasters/v3/sites/${encodedSiteUrl}/sitemaps/${sitemapUrl}`)
           if (!result.body && !result.error) {