chore: upgrade BMAD framework to skill-based architecture

Migrates from slash-command files (.claude/commands, .cursor/commands)
to the new skill-based architecture with workflow step files.

_bmad/cis/workflows/storytelling/workflow.yaml

@@ -1,26 +0,0 @@
-# Storytelling Workflow Configuration
-name: "storytelling"
-description: 'Craft compelling narratives using story frameworks. Use when the user says "help me with storytelling" or "I want to create a narrative through storytelling"'
-
-# Critical variables load from config_source
-config_source: "{project-root}/_bmad/cis/config.yaml"
-output_folder: "{config_source}:output_folder"
-user_name: "{config_source}:user_name"
-communication_language: "{config_source}:communication_language"
-date: system-generated
-
-# Context can be provided via data attribute when invoking
-# Example: data="{path}/brand-info.md" provides brand context
-
-# Module path and component files
-installed_path: "{project-root}/_bmad/cis/workflows/storytelling"
-template: "{installed_path}/template.md"
-instructions: "{installed_path}/instructions.md"
-
-# Required Data Files
-story_frameworks: "{installed_path}/story-types.csv"
-
-# Output configuration
-default_output_file: "{output_folder}/story-{{date}}.md"
-
-standalone: true