feat(audience): subscription products (Plans) wizard

[miguelpeixe]

All Submissions:

• Have you followed the Newspack Contributing guidelines?
• Does your code follow the WordPress coding standards and VIP Go coding standards?
• Have you checked to ensure there aren't other open Pull Requests for the same update/change?

Changes proposed in this Pull Request:

Adds a new "Plans" management page under Audience — a DataViews UI for managing WooCommerce Subscriptions products: name, price + billing period, active-subscriber counts, category, status, variations, group/multi-seat subscriptions, and content unlocks. List, create, and edit subscription products without leaving the wizard.

The page is gated behind the NEWSPACK_PLANS_UI feature flag and only registers when WooCommerce Subscriptions is active. It shows the plain product price — the dynamic-pricing "effective price" overlay is intentionally a separate PR (the integration), so this PR has zero dependency on the dynamic-pricing engine.

First of a three-way split of feat/rsm-pricing-rules-dataviews: (1) Plans (this PR), (2) Pricing Rules wizard, (3) the engine-pricing integration onto Plans. PRs 1 and 2 are independent; PR 3 stacks on this one.

How to test the changes in this Pull Request:

1. Add define( 'NEWSPACK_PLANS_UI', true ); to wp-config.php on a site with WooCommerce Subscriptions active.
2. Go to Audience — a Plans submenu appears. Without the flag (or without WC Subscriptions) it does not register.
3. The list shows subscription products with price/period, active-subscriber counts, category, and status. Create a new product and edit an existing one; confirm variations, group-subscription (multi-seat) settings, and content unlocks save correctly.
4. Confirm prices shown are the plain product price — there is no dynamic-pricing/effective-price column in this PR.

Other information:

• Have you added an explanation of what your changes do and why you'd like us to include them?
• Have you written new tests for your changes, as applicable?
• Have you successfully run tests with your changes locally?

[Copilot]

Pull request overview

Adds a new Audience → Plans wizard screen (gated by NEWSPACK_PLANS_UI and WooCommerce Subscriptions availability) that provides a DataViews-based UI for listing, creating, and editing WooCommerce subscription products (including variable and grouped “plan bundle” products, plus one-time donation products).

Changes:

• Registers a new Audience wizard route/component (newspack-audience-subscription-products) and conditionally boots it via NEWSPACK_PLANS_UI.
• Implements the Plans UI in React (DataViews list + routed create/edit form) with minimal scoped styling.
• Adds a new PHP wizard + REST API layer to fetch the consolidated product model and create/update products.

Reviewed changes

Copilot reviewed 10 out of 11 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
plugins/newspack-plugin/src/wizards/index.tsx	Registers the new wizard entrypoint for Plans.
plugins/newspack-plugin/src/wizards/audience/views/subscription-products/index.tsx	Adds the Plans wizard container and routes (list/new/edit).
plugins/newspack-plugin/src/wizards/audience/views/subscription-products/list.tsx	Implements the DataViews list, scopes, filters, and row actions.
plugins/newspack-plugin/src/wizards/audience/views/subscription-products/product-edit.tsx	Adds the routed wrapper that loads context and renders the form.
plugins/newspack-plugin/src/wizards/audience/views/subscription-products/product-form.tsx	Implements the full-page create/edit form and save behavior.
plugins/newspack-plugin/src/wizards/audience/views/subscription-products/types.d.ts	Adds ambient TS types for the Plans page response/model.
plugins/newspack-plugin/src/wizards/audience/views/subscription-products/style.scss	Adds minimal scoped styles for chips/forms/badges layout.
plugins/newspack-plugin/src/wizards/audience/views/subscription-products/README.md	Documents the new Plans UI/data model (needs alignment with current PR).
plugins/newspack-plugin/includes/wizards/audience/class-audience-subscription-products.php	Adds the wizard + REST endpoints and product prep/create/update logic.
plugins/newspack-plugin/includes/class-wizards.php	Conditionally registers the new wizard behind feature flag + WCS availability.
plugins/newspack-plugin/includes/class-newspack.php	Includes the new wizard PHP class file.

[miguelpeixe]

Addressed Copilot's review in 2ec87255c:

• product-edit.tsx redirect during render — moved into a useEffect so render stays pure (StrictMode-safe).
• subscription-products.php translated term names — switched to locale-independent default term names; UI labels stay translated separately.
• get_active_subscription_count() N+1 wcs_get_subscriptions() — added a per-request memo of subscription-id lists, keyed by product id, so repeated/aggregated ids resolve once.
• README.md stale "RSM prototype / Not for PR to main" header — rewritten to the shipped Plans reality.
• No Plans-specific PHPUnit tests for the create/update REST endpoints — acknowledged. Worthwhile as a follow-up: this PR reconstructs an existing branch with no upstream Plans tests, so REST-endpoint coverage is better scoped on its own rather than bundled here.