Method applyDiff

src/services/workflow-diff-engine.ts:172–351

* Apply diff operations to a workflow

(
    workflow: Workflow,
    request: WorkflowDiffRequest
  )

   * Apply diff operations to a workflow
   */
  async applyDiff(
    workflow: Workflow,
    request: WorkflowDiffRequest
  ): Promise<WorkflowDiffResult> {
    try {
      // Reset tracking for this diff operation
      this.renameMap.clear();
      this.warnings = [];
      this.modifiedNodeIds.clear();
      this.removedNodeNames.clear();
      this.tagsToAdd = [];
      this.tagsToRemove = [];
      this.transferToProjectId = undefined;

      // Clone workflow to avoid modifying original
      const workflowCopy = JSON.parse(JSON.stringify(workflow));

      const operationEntries = buildExecutionEntries(request.operations);
      const nodeOperationCount = request.operations.filter(isNodeOperation).length;
      const otherOperationCount = request.operations.length - nodeOperationCount;
      const errors: WorkflowDiffValidationError[] = [];
      const appliedIndices: number[] = [];
      const failedIndices: number[] = [];

      // Process based on mode
      if (request.continueOnError) {
        // Best-effort mode: continue even if some operations fail
        for (const { operation, index } of operationEntries) {
          const error = this.validateOperation(workflowCopy, operation);
          if (error) {
            errors.push({
              operation: index,
              message: error,
              details: operation
            });
            failedIndices.push(index);
            continue;
          }

          try {
            this.applyOperation(workflowCopy, operation);
            this.flushPendingRenames(workflowCopy);
            appliedIndices.push(index);
          } catch (error) {
            const errorMsg = `Failed to apply operation: ${error instanceof Error ? error.message : 'Unknown error'}`;
            errors.push({
              operation: index,
              message: errorMsg,
              details: operation
            });
            failedIndices.push(index);
          }
        }

        // If validateOnly flag is set, return success without applying.
        // Include workflowCopy so the caller can run structural validation against
        // the simulated post-diff result (#744).
        if (request.validateOnly) {