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/bmm/workflows/document-project/workflow.yaml

@@ -1,22 +0,0 @@
-# Document Project Workflow Configuration
-name: "document-project"
-version: "1.2.0"
-description: 'Document brownfield projects for AI context. Use when the user says "document this project" or "generate project docs"'
-author: "BMad"
-
-# Critical variables
-config_source: "{project-root}/_bmad/bmm/config.yaml"
-project_knowledge: "{config_source}:project_knowledge"
-user_name: "{config_source}:user_name"
-communication_language: "{config_source}:communication_language"
-document_output_language: "{config_source}:document_output_language"
-user_skill_level: "{config_source}:user_skill_level"
-date: system-generated
-
-# Module path and component files
-installed_path: "{project-root}/_bmad/bmm/workflows/document-project"
-instructions: "{installed_path}/instructions.md"
-validation: "{installed_path}/checklist.md"
-
-# Required data files - CRITICAL for project type detection and documentation requirements
-documentation_requirements_csv: "{installed_path}/documentation-requirements.csv"