[WIP] Premium Analytics: port WooCommerce Analytics CSV report export (test)

[layoutd]

Foundation for WOOA7S-1581

Proposed changes

• Port the WooCommerce Analytics CSV report export subsystem into the jetpack-premium-analytics package, under src/Reports/Export/.
• Registered only when WooCommerce is active and Jetpack is connected (gated on woocommerce_init + Manager::is_connected()), so it is inert on a plain Jetpack site.
• Data source re-pointed from WA's own proxy to Premium Analytics' existing data proxy: /jetpack-premium-analytics/v1/proxy/v2/analytics/{endpoint}.
• Starts with 3 report controllers (Orders, Products, Visitors) to validate the pipeline end to end.
• Route preserved as /wc/v3/woocommerce-analytics/reports/csv-export so the existing frontend export hook works unchanged.

This is a WIP / test port, not for merge. The goal is to exercise the generation endpoints on a Premium Analytics + WooCommerce store. Known follow-ups before a real PR (all part of decoupling from WooCommerce):

• Untangle the email layer from WC_Email + WC templates onto generic / Jetpack / Premium Analytics branding.
• Normalize file and class naming and the text domain to Premium Analytics conventions (class-*.php, Snake_Case, jetpack-premium-analytics); the ported files keep WA's PSR-4 names and woocommerce-analytics domain for now.
• Replace the WC-backed logger (DebugLogger wrapping WC_Logger) with a non-WC implementation for a Jetpack-only path.
• Add the remaining 12 report controllers once the pipeline is validated.

Related product discussion/links

• WOOA7S-1581: https://linear.app/a8c/issue/WOOA7S-1581/premium-analytics-data-export

Does this pull request change what data or activity we track or use?

No new tracking. It exposes existing WordPress.com analytics report data as a CSV (download or email) to authorized users (manage_options / the connected blog). The email delivery path sends report data via wp_mail; worth a privacy review before the email path is productionized.

Testing instructions

Requires WooCommerce active, Jetpack connected, and the store provisioned on WordPress.com analytics.

• Check out add/pa-report-export-test and run jetpack build plugins/premium-analytics.
• Activate Premium Analytics and WooCommerce; confirm the Jetpack connection.
• Confirm the route registers, then exercise it (as a user with manage_options):
  • POST /wp-json/wc/v3/woocommerce-analytics/reports/csv-export with report_type[]=orders, from, to, interval=day, delivery_method=download -> expect a CSV stream.
  • Repeat with report_type[]=products and report_type[]=visitors.
  • With delivery_method=email -> expect a 202 and an "export ready" email with the CSV attached (locally, catch it in Mailpit at http://localhost:1080).
• Without WooCommerce active: confirm the route is absent and the site loads normally (the gating no-ops).

[github-actions]

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Code Coverage Summary

Coverage changed in 1 file.

File	Coverage	Δ%	Δ Uncovered
projects/packages/premium-analytics/src/class-analytics.php	4/57 (7.02%)	-0.13%	1 ❤️‍🩹

19 files are newly checked for coverage. Only the first 5 are listed here.

File	Coverage
projects/packages/premium-analytics/src/Reports/Export/AbstractCSVReportController.php	0/42 (0.00%) 💔
projects/packages/premium-analytics/src/Reports/Export/CSVExportController.php	0/250 (0.00%) 💔
projects/packages/premium-analytics/src/Reports/Export/CSVExportEmail.php	0/96 (0.00%) 💔
projects/packages/premium-analytics/src/Reports/Export/CSVExportScheduler.php	0/143 (0.00%) 💔
projects/packages/premium-analytics/src/Reports/Export/CSVReportControllerInterface.php	0/1 (0.00%) 💔

Full summary · PHP report

_{If appropriate, add one of these labels to override the failing coverage check: Covered by non-unit tests Use to ignore the Code coverage requirement check when E2Es or other non-unit tests cover the code Coverage tests to be added later Use to ignore the Code coverage requirement check when tests will be added in a follow-up PR I don't care about code coverage for this PR Use this label to ignore the check for insufficient code coveage.}