fix: align spec paths from .workflow/specs to .ccw/specs

- Fix path mismatch between command files and frontend/backend spec-index-builder
- Update init-specs.md, init-guidelines.md, sync.md, solidify.md to use .ccw/specs/
- Update init.md, start.md, clean.md, unified-execute-with-file.md, collaborative-plan-with-file.md
- Add scope field to architecture-constraints.md and coding-conventions.md
- Ensures specs created by commands are visible in frontend Spec Settings page

.ccw/specs/coding-conventions.md

@@ -9,6 +9,7 @@ keywords:
   - convention
 readMode: required
 priority: high
+scope: project
 ---
 
 # Coding Conventions