Fix routing preview visualization

[VikaCep]

Problem

The alert routing preview feature was failing with the following error:

Plugin failed to load
Error: Warning: Middleware for RTK-Query API at reducerPath "notifications.alerting.grafana.app/v0alpha1" has not been added to the store.
You must add the middleware for RTK-Query to function correctly!

or

Plugin failed to load
Details
TypeError: g.current.isRequestSubscribed is not a function

    at ZE (https://plugins-cdn.grafana.net/grafana-synthetic-monitoring-app/1.43.0/public/plugins/grafana-synthetic-monitoring-app/962.93e179f421b17fdeb963.js:1044:17700)
    at div
    at div
    at Cw (https://plugins-cdn.grafana.net/grafana-synthetic-monitoring-app/1.43.0/public/plugins/grafana-synthetic-monitoring-app/962.93e179f421b17fdeb963.js:1044:37516)

depending whether it's run with Graft or without it.

This error started appearing after the 12.3.0 Grafana release. The root cause is that the useMatchInstancesToRouteTrees hook from @grafana/alerting uses RTK-Query internally, which requires middleware to be registered in the Redux store. Plugins don't have access to configure Grafana's main Redux store, and it breaks when trying to run it.

Solution

Created a custom implementation of useMatchInstancesToRouteTrees that bypasses the RTK-Query middleware requirement while maintaining full compatibility with the original hook.

The implementation:

• Manually fetches routing tree data using getBackendSrv()
• Uses the standalone matchInstancesToRouteTrees function from @grafana/alerting to process the data
• Returns the same interface as the original hook, making it a drop-in replacement

Note: This should be a temporary solution as the grafana/alerting hook should not break because of this. The alerting team has been notified of the problem.

Before:

After:

[github-actions]

Script size changes

Name	+/-	Main	This PR	Outcome
[168.js]	New file	-	1,640.30 kB	✅
[448.js]	New file	-	977.35 kB	✅
[datasource/module.js]	=	24.53 kB	24.53 kB	✅
[692.js]	=	20.57 kB	20.57 kB	✅
[663.js]	=	5.84 kB	5.84 kB	✅
[module.js]	-1.40%	4.92 kB	4.86 kB	✅
[767.js]	Deleted file	1,717.17 kB	-
[962.js]	Deleted file	976.83 kB	-

Totals

Name	+/-	Main	This PR	Outcome
[Scripts]	-2.78%	2,749.87 kB	2,673.44 kB	✅
[Non-script Assets]	=	2,668.90 kB	2,668.90 kB	✅
[All]	-1.41%	5,418.77 kB	5,342.34 kB	✅

Generated by 🚫 dangerJS against 81cf5b5

[w1kman]

LGTM 🥳

[VikaCep]

Holding off on merging because I first want to try upgrading the package/alerting version, as recommended by the alerting team (#1532)

[VikaCep]

The hook's fix is in grafana/alerting@12.4.0-20823894528 (as per grafana/grafana#116016) but it fails to publish to npm so we can't consume it. Merging this fix until we can upgrade the package's version.