Create workflows with natural language

**What the feature is (as Title)**

Create workflows with natural language

**Value proposition**

Building an automation no longer starts with a blank YAML file. Users describe the workflow they want in plain language, and AI generates it for them: the triggers, the steps, and the logic. The generated workflow is standard, fully editable YAML, so authors can refine it in the editor or keep iterating conversationally. This lowers the barrier to workflow creation so that anyone who can describe a process can automate it, not just users fluent in YAML.

**Expected outcome**

Natural language authoring moves from Tech Preview to General Availability and is enabled by default in Kibana:

- Describe a workflow in plain language and get a complete, runnable workflow
- Generated workflows use the standard workflow schema and remain fully editable
- Improved generation reliability and quality measured against real-world workflow patterns

**Optional: Key user stories / use cases**

- A SOC engineer describes an alert triage and enrichment flow and gets a working workflow to refine
- An SRE automates a recurring operational task without learning the workflow schema first