refactor: migrate forwardingStatsUploader module to TS

[jaissica12]

Background

• Continuing the effort to migrate remaining JavaScript modules in the mParticle Web SDK to TypeScript for improved type safety and developer experience. forwardingStatsUploader.js was one of the remaining JS modules.

What Has Changed

• Converted src/forwardingStatsUploader.js to src/forwardingStatsUploader.ts with type annotations
• Added IForwardingStatsUploader interface and wired it in src/mp-instance.ts
• No intentional runtime behavior, public API, or functional changes

Screenshots/Video

• N/A

Checklist

• I have performed a self-review of my own code.
• I have made corresponding changes to the documentation.
• I have added tests that prove my fix is effective or that my feature works.
• I have tested this locally.

Additional Notes

Reference Issue (For employees only. Ignore if you are an outside contributor)

• Closes https://go/j/SDKE-1194

[cursor]

PR Summary

Low Risk
Type-only refactor of internal forwarding-stats batching with no intended API or runtime behavior changes.

Overview
Migrates forwardingStatsUploader from JavaScript to TypeScript as part of the ongoing SDK TS migration.

The module now exposes IForwardingStatsUploader (with startForwardingStatsTimer()), takes IMParticleWebSDKInstance, and adds explicit typings on the batch upload path (queues, persistence table, XHR callbacks). mp-instance types _ForwardingStatsUploader against that interface instead of the concrete constructor.

For typing, the forwarding-stats interval is stored on (window.mParticle as Dictionary)._forwardingStatsTimer, and forwarderStatsTimeout is read via a Dictionary cast on SDKConfig. Upload batching and retry behavior are unchanged.

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[cursor]

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[sonarqubecloud]

Quality Gate passed

Issues
1 New issue
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[rmi22186]

Tests: unchanged (no test/ files). Core/Jest green.

Migration looks faithful — IForwardingStatsUploader wiring in mp-instance.ts is good, and window.mParticle is a clearer stand-in for the old bare global.

Nit (same theme as #1262): prefer typing the surface instead of casting:

• add forwarderStatsTimeout to SDKConfig (it’s already in Constants defaults) so you can drop (mpInstance._Store.SDKConfig as Dictionary).forwarderStatsTimeout
• type _forwardingStatsTimer on the manager/mParticle surface instead of (window.mParticle as Dictionary)

Not blocking if you want to land the rename first and follow up on types. Bugbot hits on mp-instance.ts look unrelated to this diff (import/type swap only).

[alexs-mparticle]

Can we use IMParticleWebSDKInstance here or does that cause too many cascading issues?

[alexs-mparticle]

Looks good overall. Only one question that isn't a blocker IMO