Premium Analytics: add Stats archives endpoint

[kangzj]

Fixes #

Proposed changes

• Add the Stats archives endpoint query/hook/export wiring.
• Keep endpoint-owned processing, sanitizer, fixtures, and tests in this PR where this endpoint introduces them.
• Build on the shared foundation from Premium Analytics: add Stats endpoint foundation #49886, now merged to trunk.

Related product discussion/links

• Builds on Premium Analytics: add Stats endpoint foundation #49886, now merged to trunk.
• Replaces the closed split-by-layer stack: Premium Analytics: normalize secondary Stats reports #49780, Premium Analytics: add remaining Stats hooks #49781, and Premium Analytics: add Stats app hooks #49782.

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

No. This adds client-side wrappers and normalization for existing Stats API responses.

Testing instructions

• Run pnpm --dir projects/packages/premium-analytics typecheck.
• For endpoints with processing changes, run pnpm --dir projects/packages/premium-analytics test --runInBand.
• Build coverage was checked on the foundation plus representative resource/app endpoint branches with pnpm --dir projects/packages/premium-analytics build.

Fixture coverage note

The local fixture covers the days-bucket response shape used by the archives normalizer. The summary-path behavior is typed and normalized conservatively, but there was no original endpoint fixture available to mirror that response shape in this PR.

[jp-launch-control]

Code Coverage Summary

No summary data is available for parent commit 189c92f, so cannot calculate coverage changes. 😴

If that commit is a feature branch rather than a trunk commit, this is expected. Otherwise, this should be updated once coverage for 189c92f is available.

Full summary · PHP report

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[kangzj]

Review-cycle summary — cb5ed7c085f2 → cb5ed7c085f2

1 audit round; no code changes; no actionable blocking feedback remains.

Audit details

Branch: endpoint/stats-archives-endpoint

Base: endpoint/stats-endpoint-foundation

Commits added during this audit: None.

Review feedback: Latest invited-reviewer notes are explicitly non-blocking; no inline review threads are open.

Checks: gh pr checks --required reports no required checks for this branch. The full check rollup has no failures; non-required code coverage and gardening statuses are still pending.

Unaddressed human comments: None.