[Stack Connectors] Feature filter for connector selection

[semd]

Summary

Closes https://github.com/elastic/security-team/issues/17540

Two small changes to the Connectors UI:

1. Removed getHideInUi from the HTTP connector type so it shows up in the regular connectors UIs (it was previously hidden and only available in the Workflows UI).
2. Added a "supported features" multi-select filter to the "Create connector" flyout, next to the existing search field, using EuiComboBox (with chips).
   • Options are derived dynamically from the loaded action types' supportedFeatureIds, labeled via getConnectorFeatureName.
   • Empty selection = no filtering (default).
   • When the flyout is opened with a featureId prop (e.g. from Synthetics / Uptime / rule-actions), that feature is pre-selected and the filter is disabled, so the UI matches the server-side filtering that was already being applied.

The rule-actions modal and the connectors list page are intentionally not touched.

Test plan

• Open Stack Management → Connectors → "Create connector": confirm the new feature filter is empty by default, that selecting one or more features narrows the list, and that the HTTP connector now appears.
• Open Synthetics → Settings → Alerting → "Add connector": confirm the feature filter is pre-selected with "Uptime" and is disabled.

Demos

Gravacio.de.pantalla.2026-05-28.a.les.13.08.59.mov

Gravacio.de.pantalla.2026-05-28.a.les.13.19.28.mov

[infra-vault-gh-plugin-prod]

Pinging @elastic/response-ops (Team:ResponseOps)

[Kiryous]

LGTM

[kibanamachine]

💚 Build Succeeded

• Buildkite Build
• Commit: d91fef5
• Build duration: 58 mins

Metrics [docs]

Async chunks

Total size of all lazy-loaded chunks that will be downloaded as the user navigates the app

id	before	after	diff
triggersActionsUi	2.6MB	2.6MB	+1.4KB

Page load bundle

Size of the bundles that are downloaded on every page load. Target size is below 100kb

id	before	after	diff
stackConnectors	78.5KB	78.4KB	-19.0B

History

• 💛 Build #450078 was flaky ba5c82c
• 💛 Build #449615 was flaky 5004316
• 💔 Build #449554 failed ab9014e

cc @semd