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/bmb/skills/bmad-agent-builder/assets/init-template.md

@@ -0,0 +1,47 @@
+{if-module}
+# First-Run Setup for {displayName}
+
+Welcome! Setting up your workspace.
+
+## Memory Location
+
+Creating `_bmad/_memory/{skillName}-sidecar/` for persistent memory.
+
+## Initial Structure
+
+Creating:
+- `index.md` — essential context, active work
+- `patterns.md` — your preferences I learn
+- `chronology.md` — session timeline
+
+Configuration will be loaded from your module's config.yaml.
+
+{custom-init-questions}
+
+## Ready
+
+Setup complete! I'm ready to help.
+{/if-module}
+
+{if-standalone}
+# First-Run Setup for {displayName}
+
+Welcome! Let me set up for this environment.
+
+## Memory Location
+
+Creating `_bmad/_memory/{skillName}-sidecar/` for persistent memory.
+
+{custom-init-questions}
+
+## Initial Structure
+
+Creating:
+- `index.md` — essential context, active work, saved paths above
+- `patterns.md` — your preferences I learn
+- `chronology.md` — session timeline
+
+## Ready
+
+Setup complete! I'm ready to help.
+{/if-standalone}