chore: remove BMAD framework files and IDE configuration artifacts

Clean up unused BMAD workflow, agent, and command files across all IDE
configurations (.agent, .clinerules, .cursor, .gemini, .github, .kilocode,
.opencode) and internal module files (_bmad/bmb, _bmad/bmm).

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.opencode/skills/bmad-init/resources/core-module.yaml

@@ -0,0 +1,25 @@
+code: core
+name: "BMad Core Module"
+
+header: "BMad Core Configuration"
+subheader: "Configure the core settings for your BMad installation.\nThese settings will be used across all installed bmad skills, workflows, and agents."
+
+user_name:
+  prompt: "What should agents call you? (Use your name or a team name)"
+  default: "BMad"
+  result: "{value}"
+
+communication_language:
+  prompt: "What language should agents use when chatting with you?"
+  default: "English"
+  result: "{value}"
+
+document_output_language:
+  prompt: "Preferred document output language?"
+  default: "English"
+  result: "{value}"
+
+output_folder:
+  prompt: "Where should output files be saved?"
+  default: "_bmad-output"
+  result: "{project-root}/{value}"