Studio Sync: Implement resumable uploads for sync archives

[gavande1]

Related issues

• Fixes STU-939

Proposed Changes

• Implements resumable uploads for sync archives using Tus Protocol.
• Reverts changes added in Execute /studio-app/sync/import network request from node process #1972 as uploading happens in frontend.

Testing Instructions

• Checkout 197246-ghe-Automattic/wpcom and 196922-ghe-Automattic/wpcom on your sandbox. You probably need to use git checkout branch -- filenames for applying changes from two branches.
• Sandbox public-api.wordpress.com and makes it's in FULL ACCESS mode.
• Checkout this branch in Studio
• run npm install & install start
• Connect your wordpress.com
• Add site for sync
• Run following tests

1. Do a full sync
2. Do a partial sync with different options
3. Start sync, go offline, wait few seconds, come online again. Make sure sync doesn't fail. This is to confirm resumable capability.

• Checkout to master branch on Studio
• Run above tests again. Everything should work. The code handles backward compatibility.

CleanShot.2025-12-02.at.18.44.24.mp4

Additional checks:

• Check for any abnormal behavior from existing setup.
• Check if you can not upload more than 2 GB of archive.
• Make sure you receive success email after sync is completed.

Pre-merge Checklist

• Have you checked for TypeScript, React or other console errors?

[github-actions]

📊 Performance Test Results

Comparing d01c2bf vs trunk

site-editor

Metric	trunk	d01c2bf	Diff	Change
load	11400.00 ms	8618.00 ms	-2782.00 ms	🟢 -24.4%

site-startup

Metric	trunk	d01c2bf	Diff	Change
siteCreation	96038.00 ms	84333.00 ms	-11705.00 ms	🟢 -12.2%
siteStartup	39597.00 ms	38654.00 ms	-943.00 ms	🟢 -2.4%

---

Results are median values from multiple test runs.

Legend: 🟢 Improvement (faster) | 🔴 Regression (slower) | ⚪ No change

[gavande1]

I still need to look into how we can resolve this typescript error. The tests are also failing because of this.