fix(skills): normalize create-product-brief metadata refs

src/bmm/agents/analyst.agent.yaml

@@ -35,7 +35,7 @@ agent:
       description: "[TR] Technical Research: Technical feasibility, architecture options and implementation approaches"
 
     - trigger: CB or fuzzy match on product-brief
-      exec: "{project-root}/_bmad/bmm/workflows/1-analysis/bmad-create-product-brief/workflow.md"
+      exec: "skill:bmad-create-product-brief"
       description: "[CB] Create Brief: A guided experience to nail down your product idea into an executive brief"
 
     - trigger: DP or fuzzy match on document-project

src/bmm/workflows/1-analysis/bmad-create-product-brief/workflow.md

@@ -1,8 +1,3 @@
----
-name: bmad-create-product-brief
-description: 'Create product brief through collaborative discovery. Use when the user says "lets create a product brief" or "help me create a project brief"'
----
-
 # Product Brief Workflow
 
 **Goal:** Create comprehensive product briefs through collaborative step-by-step discovery as creative Business Analyst working with the user as peers.