refactor(templates): rename architecture placeholder to bmad_architecture for consistency

Update placeholder name in template files and configuration to use more specific naming convention

Author: moazbuilds

config/placeholders.js

@@ -19,7 +19,7 @@ module.exports = {
     product_brief: path.join('.codemachine', 'artifacts', 'product-brief-*.md'),
     prd: path.join('.codemachine', 'artifacts', 'prd-*.md'),
     ux_design_spec: path.join('.codemachine', 'artifacts', 'ux-design-spec-*.md'),
-    architecture: path.join('.codemachine', 'artifacts', 'architecture-*.md'),
+    bmad_architecture: path.join('.codemachine', 'artifacts', 'architecture-*.md'),
     epics: path.join('.codemachine', 'artifacts', 'epics-*.md'),
   },
 

prompts/templates/bmad/02-pm/02-epics/workflow.md

@@ -27,7 +27,7 @@ This uses **step-file architecture** for disciplined execution:
 
 ## ARCHITECTURE
 
-{architecture}
+{bmad_architecture}
 
 ## UX DESIGN SPECIFICATION
 

prompts/templates/bmad/02-pm/03-readiness/workflow.md

@@ -27,7 +27,7 @@ This uses **step-file architecture** for disciplined execution:
 
 ## ARCHITECTURE
 
-{architecture}
+{bmad_architecture}
 
 ## EPICS
 

prompts/templates/bmad/06-sm/02-create-story/instructions.xml

@@ -24,7 +24,7 @@
 
 ## Architecture
 
-{architecture}
+{bmad_architecture}
 
 ## UX Design Specification