feat(workflow) - Add validation layer (#21422)

Add workflow validation framework and consolidate output schema
types/search logic into twenty-shared

This PR introduces a comprehensive workflow validation system that
catches configuration errors at build-time, and consolidates the
fragmented output-schema type definitions and variable-search logic from
the front-end into twenty-shared

**Workflow validation** — A new system that checks workflows for errors
before activation: graph connectivity (unreachable steps, dangling
references), step parameter schemas (via Zod), variable references
(typos, wrong step order), and workspace metadata (non-existent
objects). Returns structured errors/warnings with "did you mean?"
suggestions. Runs automatically after create_complete_workflow and
update_workflow_version_step, and is also available as a standalone
validate_workflow tool.

**Output schema consolidation** — Moves all output schema types and the
variable-search logic from scattered front-end files into twenty-shared,
replacing ~800 lines of duplicated per-schema-type code with a single
unified searchVariableInOutputSchema dispatcher.


To do : 
- validation on CODE and AGENT step

---------

Co-authored-by: Cursor <cursoragent@cursor.com>

packages/twenty-shared/src/workflow/schemas/base-workflow-action-schema.ts

@@ -2,9 +2,9 @@ import { z } from 'zod';
 
 export const baseWorkflowActionSchema = z.object({
   id: z
-    .string()
+    .uuid()
     .describe(
-      'Unique identifier for the workflow step. Must be unique within the workflow.',
+      'Unique UUID identifier for the workflow step. Must be a valid UUID v4, unique within the workflow.',
     ),
   name: z
     .string()
@@ -17,7 +17,7 @@ export const baseWorkflowActionSchema = z.object({
       'Whether the step configuration is valid. Set to true when all required fields are properly configured.',
     ),
   nextStepIds: z
-    .array(z.string())
+    .array(z.uuid())
     .optional()
     .nullable()
     .describe(