Add multisite warning to push dialog for WordPress.com targets

[bcotrim]

Related issues

• Fixes STU-1377

How AI was used in this PR

Implementation was AI-assisted. All code was reviewed and iterated on manually.

Proposed Changes

• Add multisite detection utility that reads wp-config.php for the MULTISITE constant
• Add getIsMultisite IPC handler and useIsMultisite React hook (same pattern as getWpVersion/useGetWpVersion)
• Show a non-blocking warning in the push dialog when pushing a multisite site to WordPress.com (Pressable is excluded since it supports multisite)
• Refactor push dialog warnings into a collapsible "N warnings — Show/Hide" section to keep the UI clean when multiple warnings are present
• Replace the semi-transparent blurred bottom bar with an opaque background for better readability

Push (hidden)	Push	Preview Sites

Testing Instructions

• Import a blueprint with "step": "enableMultisite" to create a multisite site
• Connect the site to a WordPress.com site
• Open the Push dialog — verify the multisite warning appears in a collapsible warnings section
• Click "Hide" to collapse warnings, click "Show" to expand — verify the toggle works and padding adjusts
• If a version mismatch warning is also present, verify both warnings show with a "2 warnings" label
• Connect to a Pressable site instead — verify the multisite warning does NOT appear
• Open a Pull dialog — verify no warnings section appears
• Run npm test -- tools/common/lib/tests/is-multisite.test.ts — all 7 tests pass

Pre-merge Checklist

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

[wpmobilebot]

📊 Performance Test Results

Comparing 0f71438 vs trunk

app-size

Metric	trunk	0f71438	Diff	Change
App Size (Mac)	1249.54 MB	1249.55 MB	+0.01 MB	⚪ 0.0%

site-editor

Metric	trunk	0f71438	Diff	Change
load	1863 ms	1929 ms	+66 ms	🔴 3.5%

site-startup

Metric	trunk	0f71438	Diff	Change
siteCreation	8184 ms	8206 ms	+22 ms	⚪ 0.0%
siteStartup	4851 ms	4946 ms	+95 ms	🔴 2.0%

---

Results are median values from multiple test runs.

Legend: 🟢 Improvement (faster) | 🔴 Regression (slower) | ⚪ No change (<50ms diff)

[katinthehatsite]

I am not sure if it is me but this is looking slightly misaligned for me by a couple of pixels:

e.g. Hide and Show seem slightly higher than the warning

[katinthehatsite]

Thanks for all the changes - I like that there is an option to hide the warnings so that they are not taking too much space. Should we slightly drop the space below the database when the modal is open?

I am also wondering - do you know if multisites could create unexpected issues for the preview sites?

[katinthehatsite]

Another question that I forgot to add to the review: I am currently seeing that when you open the modal, it shows by default the warnings and then you can hide them. Should we hide them by default so that they don't initially take too much space and then the user can open the later?

[bcotrim]

Thanks for the review @katinthehatsite
I've made some changes to the layout and added the same warning on preview sites (it already existed for mismatched PHP/WordPress versions)
Can you take another look, please?

Another question that I forgot to add to the review: I am currently seeing that when you open the modal, it shows by default the warnings and then you can hide them. Should we hide them by default so that they don't initially take too much space and then the user can open the later?

It was intentional, since it could be an operation that breaks the production site, I think having them open by default increases the chance our users won't miss it.
What do you think?

[katinthehatsite]

It was intentional, since it could be an operation that breaks the production site, I think having them open by default increases the chance our users won't miss it.
What do you think?

I don't have a strong opinion as I can see the benefits either way. I will give it another review 👀

[katinthehatsite]

I have retested it and I think it looks and works better. Also thanks for adding it to the preview sites 👍

I am not sure what is the expected design for this though. It might be worth confirming this with design. On my side, I don't have any further comments

[sejas]

Works as expected. I see the warning when pushing to WPcom but not to Pressable. I also see a warning when creating a preview site.

Push WPcom	Push Pressable	Preview site