fix: Correct workflow-session.json path references in brainstorming docs

- Fix incorrect path: .brainstorming/workflow-session.json → /workflow-session.json
- Update 8 role files: data-architect, product-manager, product-owner, scrum-master,
  subject-matter-expert, ui-designer, ux-expert, auto-parallel
- Update artifacts.md to clarify correct session file location
- Align all paths with workflow-architecture.md standard structure

Fixes session file path confusion issue. workflow-session.json should be at
session root (.workflow/WFS-{session}/), not in .brainstorming/ subdirectory.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

.claude/commands/workflow/brainstorm/scrum-master.md

@@ -88,7 +88,7 @@ ANALYSIS_MODE: {framework_mode ? "framework_based" : "standalone"}
 
 3. **load_session_metadata**
    - Action: Load session metadata and existing context
-   - Command: Read(.workflow/WFS-{session}/.brainstorming/session.json)
+   - Command: Read(.workflow/WFS-{session}/workflow-session.json)
    - Output: session_context
 
 ## Analysis Requirements
@@ -136,7 +136,7 @@ TodoWrite({
       activeForm: "Generating structured scrum-master analysis"
     },
     {
-      content: "Update session.json with scrum-master completion status",
+      content: "Update workflow-session.json with scrum-master completion status",
       status: "pending",
       activeForm: "Updating session metadata"
     }