Can I vibe code Yieldify?

Build a custom, lightweight onsite lead capture and personalization engine to replace Yieldify. The system consists of three parts: a Next.js admin dashboard, a serverless API backend, and an ultra-lightweight vanilla JS embed script (<15KB).

1. Database Schema (Supabase/PostgreSQL):
- `campaigns`: id, name, trigger_type (exit_intent, time_delay, scroll_depth, cart_value), trigger_value, target_url_pattern, delay_seconds, max_impressions_per_user, html_content, css_styles, is_active.
- `leads`: id, campaign_id, email, metadata (jsonb), coupon_assigned, created_at.
- `analytics_events`: id, campaign_id, event_type (impression, conversion, close), session_id, created_at.

2. Embed Script (`sdk.js`):
- Injected via single script tag. Uses Shadow DOM to isolate styles from the store theme.
- Reads cart data from window object or cookie (e.g., `cart_total`).
- Listens for desktop exit intent (`mouseleave` on `document.documentElement` where `clientY <= 0`), mobile scroll-up spikes, or timers.
- Checks `localStorage` for frequency caps (`campaign_{id}_converted`, `campaign_{id}_shown_count`).
- Renders responsive popup modal upon rule match. On form submit, sends POST request to API, sets conversion flag in `localStorage`, displays discount code inline.

3. Backend API Routes:
- `/api/v1/campaigns`: Serves active campaigns matching domain header.
- `/api/v1/lead`: Validates email via regex, logs lead to database, triggers Klaviyo API v3 `/api/profile-subscription-bulk-create-jobs` with user tags, and returns active promo code.
- `/api/v1/event`: Asynchronously logs impression and conversion events for analytics.

4. Admin Portal:
- Next.js dashboard listing active campaigns with basic impression, conversion, and conversion-rate metrics.
- Simple visual editor allowing raw HTML/CSS input or pre-designed templates (Email Capture, Exit Offer, Free Shipping Bar).

5. Edge Cases & Failure Modes:
- If Klaviyo API is unreachable, store lead locally and flag `synced: false` for background retries.
- Prevent script blocking main thread; all DOM evaluation must be deferred or asynchronous.

6. Out of Scope:
- Drag-and-drop canvas layout editor (use structured forms + custom HTML/CSS).
- Native SMS dispatching (delegate to Klaviyo).

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