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-server/src/engine/core-modules/workflow/dtos/create-workflow-version-step.input.ts

@@ -6,7 +6,7 @@ import { UUIDScalarType } from 'src/engine/api/graphql/workspace-schema-builder/
 import { WorkflowStepPositionInput } from 'src/engine/core-modules/workflow/dtos/update-workflow-step-position.input';
 import { WorkflowStepConnectionOptions } from 'src/modules/workflow/workflow-builder/workflow-version-step/types/WorkflowStepCreationOptions';
 import { WorkflowActionSettings } from 'src/modules/workflow/workflow-executor/workflow-actions/types/workflow-action-settings.type';
-import { WorkflowActionType } from 'src/modules/workflow/workflow-executor/workflow-actions/types/workflow-action.type';
+import { WorkflowActionType } from 'twenty-shared/workflow';
 
 @InputType()
 export class CreateWorkflowVersionStepInput {

packages/twenty-server/src/engine/core-modules/workflow/dtos/workflow-action.dto.ts

@@ -4,7 +4,7 @@ import graphqlTypeJson from 'graphql-type-json';
 
 import { UUIDScalarType } from 'src/engine/api/graphql/workspace-schema-builder/graphql-types/scalars';
 import { WorkflowStepPosition } from 'src/engine/core-modules/workflow/dtos/workflow-step-position.dto';
-import { WorkflowActionType } from 'src/modules/workflow/workflow-executor/workflow-actions/types/workflow-action.type';
+import { WorkflowActionType } from 'twenty-shared/workflow';
 
 registerEnumType(WorkflowActionType, {
   name: 'WorkflowActionType',

packages/twenty-server/src/engine/workspace-manager/twenty-standard-application/utils/skill-metadata/create-standard-flat-skill-metadata.util.ts

@@ -74,6 +74,11 @@ Always rely on tool schema definitions:
 - Follow schema definitions exactly for field names, types, and structures
 - Schema includes validation rules and common patterns
 
+## Validation
+
+The \`create_complete_workflow\` and \`update_workflow_version_step\` tools automatically run validation after their operation and include the results in the response. Review any reported errors and fix them before activating the workflow.
+
+
 ## Approach
 
 - Ask clarifying questions to understand user needs