Premium Analytics: add Stats subscribers endpoints

[kangzj]

Fixes #

Proposed changes

• Add Premium Analytics data package support for the Stats subscribers endpoint, following the Stats endpoint patterns established in Premium Analytics: add Stats endpoint foundation #49886.
• Wire the endpoint-specific query, hook, public exports, and sanitizer/normalizer registration where applicable.
• Keep endpoint typing tied to sanitizer keys or passthrough query inference, with focused fixtures/tests for the raw endpoint payload shape where normalization is introduced.

Related product discussion/links

• Builds on Premium Analytics: add Stats endpoint foundation #49886.

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

No. This only adds typed client data/query integration for an existing Stats API endpoint.

Testing instructions

• pnpm --dir projects/packages/premium-analytics test -- packages/data/src/queries/tests/stats-queries.test.ts packages/data/src/hooks/tests/stats-exports.test.ts --runInBand
• pnpm exec eslint --max-warnings=0
• pnpm --dir projects/packages/premium-analytics run typecheck
• git diff --check

[jp-launch-control]

Code Coverage Summary

This PR did not change code coverage!

That could be good or bad, depending on the situation. Everything covered before, and still is? Great! Nothing was covered before? Not so great. 🤷

Full summary · PHP report

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[kangzj]

Review-cycle audit complete: no actionable owner or invited-AI feedback remains, required checks are reported as none for this branch, and the PR is ready for team review. Only Claude's optional cosmetic import-ordering note remains.