Add electron devtools installer back

[wojtekn]

Related issues

• Follow-up to Replace electron-devtools-installer with native Electron API #2307

Proposed Changes

PR #2307 removed electron-devtools-installer due to deprecated Electron APIs, replacing it with a custom implementation. However, this broke the automatic extension installation for new developers.

This PR takes a different approach by patching electron-devtools-installer to use the new Electron APIs (session.extensions.*) instead of the deprecated ones (session.*). This solution:

• Eliminates deprecation warnings
• Maintains automatic extension installation
• Uses the well-tested and maintained electron-devtools-installer package
• Applies the fix from upstream commit f8ec609 (not yet released)

Testing Instructions

1. Start the app and confirm:

• Extensions should install automatically
• No deprecation warnings should appear in the console

2. Verify extensions work:

• Open DevTools (Cmd+Option+I / Ctrl+Shift+I)
• Check for "Redux" tab (Redux DevTools)

Pre-merge Checklist

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

[wpmobilebot]

📊 Performance Test Results

Comparing 596195a vs trunk

site-editor

Metric	trunk	596195a	Diff	Change
load	2883.00 ms	2864.00 ms	-19.00 ms	🟢 -0.7%

site-startup

Metric	trunk	596195a	Diff	Change
siteCreation	8087.00 ms	7122.00 ms	-965.00 ms	🟢 -11.9%
siteStartup	3942.00 ms	3947.00 ms	+5.00 ms	🔴 0.1%

---

Results are median values from multiple test runs.

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

[bcotrim]

I was able to start the app without seeing any errors.
I am not sure if this was happening previously, but starting the app with devtools already opened doesn't show React DevTools.
I remember that previously we had this workaround: https://github.com/Automattic/studio/pull/1379/changes#diff-a2a171449d862fe29692ce031981047d7ab755ae7f84c707aef80701b3ea0c80R105
Maybe we still need that?

Doing a refresh ( cmd + R) displays the React DevTools as expected

[bcotrim]

I couldn't find this file in the scripts folder.

[wojtekn]

Good catch! It seems that the change from another PR slipped in. I removed this line.

[wojtekn]

Maybe we still need that?

That code was still there. I adjusted it, but I'm unsure if it helps - it still required me to run CMD+R to refresh it at least one. On subsequent runs, it shows without that refresh.

[bcotrim]

That code was still there. I adjusted it, but I'm unsure if it helps - it still required me to run CMD+R to refresh it at least one. On subsequent runs, it shows without that refresh.

Thanks for following up on that!
I can replicate the same behavior, but it also happens in trunk. Since the original goal of this PR is working I think we can address that issue as a follow-up, if necessary.