Sanitize analytics payloads to prevent circular JSON errors

[gansxx]

Motivation

• Third-party analytics (GTM/PostHog/Zaraz) received raw event payloads that could contain DOM nodes, browser Events or React internals, causing TypeError: Converting circular structure to JSON when JSON.stringify is attempted.
• The change prevents sending non-serializable or excessively large data to analytics providers and avoids runtime exceptions in the browser.
• Also fixed a nested-anchor markup issue in the app store card that could create invalid DOM structure.

Description

• Add lib/analytics-sanitize.ts which converts Event and HTMLElement values into JSON-safe metadata, strips React internal keys, guards against circular references, enforces max depth, array length and string length limits, and normalizes keys.
• Sanitize payloads pushed to the GTM dataLayer in lib/gtm/utils.ts by calling sanitizeAnalyticsProperties and pushing only the sanitized object.
• Sanitize parameters passed to GA (gtag) and PostHog: update lib/analytics.ts to use sanitized safeParams, and lib/posthog.ts to forward sanitized properties to posthog.capture.
• Fix components/AppStoreCard.tsx to avoid nested <a> elements by moving the icon/name outside the anchor and linking the download Button directly to the external href.

Testing

• pnpm build completed successfully (Next.js production build and static generation succeeded). ✅
• pnpm exec tsc --noEmit still reports unrelated pre-existing type errors in other parts of the repo (e.g. OrdersTable, subscription-error-alert, subscription-api) and therefore did not fully pass here. ⚠️
• pnpm lint (next lint) is interactive in this repo and could not complete automatically in CI; it did not run to completion. ⚠️
• Manual verification: build output shows app compiles and static pages generated; core change prevents circular structures from being forwarded to analytics providers and fixes the nested anchor issue. ✅

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Codex Task

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Project	Deployment	Actions	Updated (UTC)
vpn_web	Ready	Preview, Comment, Open in v0	May 17, 2026 4:52am