[Search][WIP] Move ai.prompt, ai.summarize, ai.classify workflows to inference plugin (elastic#269392)

## Summary

Resolves elastic/search-team#14019

Moves the three AI workflow steps (`ai.prompt`, `ai.summarize`,
`ai.classify`) from the `workflowsExtensions` plugin to a new
`inferenceWorkflows` plugin owned by `@elastic/search-kibana`.

- Created new `inferenceWorkflows` plugin at
`x-pack/platform/plugins/shared/inference_workflows/`
- Steps are registered via the external
`workflowsExtensions.registerStepDefinition()` API (same pattern as
`agent_builder`)
- Registers workflows AI features with `searchInferenceEndpoints` so
admins can configure model restrictions per step on the Inference
Endpoints settings page
- Removed AI step code from `workflows_extensions` — it now only
contains data.* steps
- Updated CODEOWNERS, i18n config, optimizer limits, and README

### Why a new plugin?

The `inference` plugin cannot depend on `workflowsExtensions` (circular
dependency — `workflowsExtensions` already depends on `inference`). A
dedicated plugin keeps dependencies flowing in the right direction and
gives the search team clear ownership.

### What changed

| Area | Before | After |
|------|--------|-------|
| AI step registration | Internal in `workflowsExtensions` | External
via `inferenceWorkflows` plugin |
| License | SSPL triple-license (`src/`) | Elastic License 2.0
(`x-pack/`) |
| i18n prefix | `workflowsExtensionsExample.*` |
`xpack.inferenceWorkflows.*` |
| Inference feature registration | `workflowsExtensions` (stale after
merge) | `inferenceWorkflows` plugin setup |
| Step logic | **Unchanged** | **Unchanged** |

### Checklist

Check the PR satisfies following conditions.

Reviewers should verify this PR satisfies this list as well.

- [ ] Any text added follows [EUI's writing
guidelines](https://elastic.github.io/eui/#/guidelines/writing), uses
sentence case text and includes [i18n
support](https://github.com/elastic/kibana/blob/main/src/platform/packages/shared/kbn-i18n/README.md)
- [ ]
[Documentation](https://www.elastic.co/guide/en/kibana/master/development-documentation.html)
was added for features that require explanation or tutorials
- [x] [Unit or functional
tests](https://www.elastic.co/guide/en/kibana/master/development-tests.html)
were updated or added to match the most common scenarios
- [ ] If a plugin configuration key changed, check if it needs to be
allowlisted in the cloud and added to the [docker
list](https://github.com/elastic/kibana/blob/main/src/dev/build/tasks/os_packages/docker_generator/resources/base/bin/kibana-docker)
- [x] This was checked for breaking HTTP API changes, and any breaking
changes have been approved by the breaking-change committee. The
`release_note:breaking` label should be applied in these situations.
- [ ] [Flaky Test
Runner](https://ci-stats.kibana.dev/trigger_flaky_test_runner/1) was
used on any tests changed
- [x] The PR description includes the appropriate Release Notes section,
and the correct `release_note:*` label is applied per the
[guidelines](https://www.elastic.co/guide/en/kibana/master/contributing.html#kibana-release-notes-process)
- [x] Review the [backport
guidelines](https://docs.google.com/document/d/1VyN5k91e5OVumlc0Gb9RPa3h1ewuPE705nRtioPiTvY/edit?usp=sharing)
and apply applicable `backport:*` labels.

## Test plan

- [x] 160 unit tests pass in the new location
- [ ] Verify AI steps appear in the workflow editor UI
- [ ] Verify connector-id selection works for all three steps
- [ ] Verify AI steps appear under Workflows AI on the Inference
Endpoints settings page
- [ ] Verify in serverless mode
- [ ] Update `approved_step_definitions.ts` handler hashes after CI
build

🤖 Generated with [Claude Code](https://claude.com/claude-code)

---------

Co-authored-by: kibanamachine <42973632+kibanamachine@users.noreply.github.com>

Author: 2 people

.github/CODEOWNERS

@@ -1190,6 +1190,7 @@ x-pack/platform/plugins/shared/inbox @elastic/security-genai-research-and-develo
 x-pack/platform/plugins/shared/index_management @elastic/kibana-management
 x-pack/platform/plugins/shared/inference @elastic/search-kibana
 x-pack/platform/plugins/shared/inference_endpoint @elastic/search-kibana
+x-pack/platform/plugins/shared/inference_workflows @elastic/search-kibana
 x-pack/platform/plugins/shared/ingest_hub @elastic/obs-onboarding-team
 x-pack/platform/plugins/shared/ingest_pipelines @elastic/kibana-management
 x-pack/platform/plugins/shared/lens @elastic/kibana-visualizations

docs/extend/plugin-list.md

@@ -173,6 +173,7 @@ mapped_pages:
 | [indicesMetadata](https://github.com/elastic/kibana/blob/main/x-pack/platform/plugins/private/indices_metadata/README.md) | Plugin for managing and retrieving metadata about indices in Kibana. This plugin collects and processes metadata from Elasticsearch indices, data streams, ILM policies, and index templates. |
 | [inference](https://github.com/elastic/kibana/blob/main/x-pack/platform/plugins/shared/inference/README.md) | The inference plugin is a central place to handle all interactions with the Elasticsearch Inference API and external LLM APIs. Its goals are: |
 | [inferenceEndpoint](https://github.com/elastic/kibana/blob/main/x-pack/platform/plugins/shared/inference_endpoint/README.md) | A Kibana plugin |
+| [inferenceWorkflows](https://github.com/elastic/kibana/blob/main/x-pack/platform/plugins/shared/inference_workflows/README.md) | Registers AI workflow steps (ai.prompt, ai.summarize, ai.classify) that use the inference plugin to power LLM-based automation in Kibana Workflows. |
 | [infra](https://github.com/elastic/kibana/blob/main/x-pack/solutions/observability/plugins/infra/README.md) | This is the home of the infra plugin, which aims to provide a solution for the infrastructure monitoring use-case within Kibana. |
 | [ingestHub](https://github.com/elastic/kibana/blob/main/x-pack/platform/plugins/shared/ingest_hub/README.md) | Cross-solution onboarding page for adding data sources and integrations. Gated behind the ingestHub.enabled feature flag. |
 | [ingestPipelines](https://github.com/elastic/kibana/blob/main/x-pack/platform/plugins/shared/ingest_pipelines/README.md) | The ingest_pipelines plugin provides Kibana support for Elasticsearch's ingest pipelines. |

package.json

@@ -762,6 +762,7 @@
     "@kbn/inference-prompt-utils": "link:x-pack/platform/packages/shared/kbn-inference-prompt-utils",
     "@kbn/inference-tracing": "link:x-pack/platform/packages/shared/kbn-inference-tracing",
     "@kbn/inference-tracing-config": "link:x-pack/platform/packages/shared/kbn-inference-tracing-config",
+    "@kbn/inference-workflows-plugin": "link:x-pack/platform/plugins/shared/inference_workflows",
     "@kbn/infra-forge": "link:x-pack/platform/packages/private/kbn-infra-forge",
     "@kbn/infra-plugin": "link:x-pack/solutions/observability/plugins/infra",
     "@kbn/ingest-hub-plugin": "link:x-pack/platform/plugins/shared/ingest_hub",

packages/kbn-optimizer/limits.yml

@@ -91,6 +91,7 @@ pageLoadAssetSize:
   indexLifecycleManagement: 47110
   indexManagement: 39694
   inference: 10368
+  inferenceWorkflows: 25000
   infra: 56302
   ingestHub: 13422
   ingestPipelines: 17866

packages/kbn-rspack-optimizer/limits.yml

@@ -90,7 +90,8 @@ pageLoadAssetSize:
   inbox: 1294
   indexLifecycleManagement: 39553
   indexManagement: 316
-  inference: 5564
+  inference: 5751
+  inferenceWorkflows: 25000
   infra: 45673
   ingestHub: 1923
   ingestPipelines: 270

src/platform/plugins/shared/workflows_extensions/common/steps/index.ts

@@ -7,5 +7,4 @@
  * License v3.0 only", or the "Server Side Public License, v 1".
  */
 
-export * from './ai';
 export * from './data';

src/platform/plugins/shared/workflows_extensions/kibana.jsonc

@@ -11,8 +11,6 @@
     "browser": true,
     "server": true,
     "requiredPlugins": ["actions", "inference", "spaces"],
-    "optionalPlugins": ["searchInferenceEndpoints"],
     "extraPublicDirs": ["common"]
   }
 }
-

src/platform/plugins/shared/workflows_extensions/moon.yml

@@ -25,7 +25,6 @@ dependsOn:
   - '@kbn/scout'
   - '@kbn/i18n'
   - '@kbn/inference-plugin'
-  - '@kbn/inference-common'
   - '@kbn/actions-plugin'
   - '@kbn/utility-types'
   - '@kbn/spaces-plugin'
@@ -35,7 +34,6 @@ dependsOn:
   - '@kbn/logging-mocks'
   - '@kbn/logging'
   - '@kbn/core-http-common'
-  - '@kbn/search-inference-endpoints'
 tags:
   - plugin
   - prod

src/platform/plugins/shared/workflows_extensions/public/steps/index.ts

@@ -29,13 +29,6 @@ export const registerInternalStepDefinitions = (stepRegistry: PublicStepRegistry
   stepRegistry.register(() =>
     import('./data/data_aggregate_step').then((m) => m.dataAggregateStepDefinition)
   );
-  stepRegistry.register(() => import('./ai/ai_prompt_step').then((m) => m.AiPromptStepDefinition));
-  stepRegistry.register(() =>
-    import('./ai/ai_summarize_step').then((m) => m.AiSummarizeStepDefinition)
-  );
-  stepRegistry.register(() =>
-    import('./ai/ai_classify_step').then((m) => m.AiClassifyStepDefinition)
-  );
   stepRegistry.register(() =>
     import('./data/data_stringify_json_step').then((m) => m.dataStringifyJsonStepDefinition)
   );

src/platform/plugins/shared/workflows_extensions/server/plugin.ts

@@ -25,7 +25,6 @@ import { registerGetStepDefinitionsRoute } from './routes/get_step_definitions';
 import { registerGetTriggerDefinitionsRoute } from './routes/get_trigger_definitions';
 import { ServerStepRegistry } from './step_registry';
 import { registerInternalStepDefinitions } from './steps';
-import { registerInferenceFeatures } from './steps/ai/register_inference_features';
 import { TriggerRegistry } from './trigger_registry';
 import { registerInternalTriggerDefinitions } from './triggers';
 import type {
@@ -78,13 +77,9 @@ export class WorkflowsExtensionsServerPlugin
     registerGetStepDefinitionsRoute(router, this.stepRegistry);
     registerGetTriggerDefinitionsRoute(router, this.triggerRegistry);
 
-    registerInternalStepDefinitions(core, this.stepRegistry);
+    registerInternalStepDefinitions(this.stepRegistry);
     registerInternalTriggerDefinitions(this.triggerRegistry);
 
-    if (plugins.searchInferenceEndpoints) {
-      registerInferenceFeatures(plugins.searchInferenceEndpoints);
-    }
-
     return {
       registerStepDefinition: (definition) => {
         this.stepRegistry.register(definition);