Block Marketplace: install third-party blocks on your sites

The Block Marketplace at /marketplace/blocks is where you browse and install blocks built by other Turtini orgs. Once installed on your org, marketplace blocks appear in the Builder picker alongside first-party blocks and render on your published sites exactly like built-in blocks.

Browsing:
• Search across labels + descriptions
• Filter by Free / Paid
• Filter by category (Marketing, Commerce, etc.)
• Each card shows install count, version, and price

Previewing before you install:
Click "Preview" on any block card. The block renders inside a sandboxed iframe using its published default field values — you see exactly what visitors would see, with no commitment.

Installing — three pricing models:
1. Free → installs immediately, no checkout
2. One-time purchase → Stripe Embedded Checkout opens in a modal. The block activates the instant payment succeeds (webhook-driven). 90% of the purchase price routes to the creator's Stripe Connect account; 10% goes to the platform.
3. Subscription → Stripe creates a recurring subscription on your org's existing Stripe customer. You're billed monthly (or yearly), and rev share (90/10 default) is auto-routed by Stripe on every invoice via application_fee_percent.

After install:
• The block doesn't appear in the Builder picker yet (Phase 1 — listing in v2). In v3, installed marketplace blocks merge into the picker.
• On any already-published page that uses the block (or after you add a new section with the block's namespaced type — e.g. 'pixel-studios.testimonial-carousel'), the runtime resolves the install record and renders the block in its sandbox.

Uninstalling:
Click "Uninstall" on the installed card. For subscriptions, Stripe is told to cancel at period end — you keep access until the period closes, then the block is automatically suspended. For one-time installs, the block is suspended immediately (no refund — that's a manual support request).

Suspended blocks:
If the platform suspends a block (security incident, refund batch), pages that use it render an amber "this marketplace block was suspended" placeholder. You can replace or remove the block to clean up.