refactor: consolidate workflow documentation into unified architecture

- Create unified workflow-architecture.md combining:
  - data-model.md (JSON-only architecture, task schemas)
  - file-structure-standards.md (progressive structures, templates)
  - session-management-principles.md (marker files, session ops)
  - complexity-rules.md (classification thresholds, behaviors)

- Update 11 files with references to new consolidated document
- Remove redundant documentation while preserving all functionality
- Streamline maintenance with single source of truth

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

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

.claude/commands/gemini/execute.md

@@ -198,7 +198,7 @@ This template is automatically filled and generated after execution.
     - **IF active session exists**: Save to existing `.workflow/WFS-[topic-slug]/.chat/` directory
     - **IF no active session**: Create new session directory following WFS naming convention
 
-**Session Management**: @~/.claude/workflows/session-management-principles.md
+**Session Management**: @~/.claude/workflows/workflow-architecture.md
 -   **File Format**: `execute-YYYYMMDD-HHMMSS.md` with timestamp for unique identification.
 -   **Structure**: Integrates with session management system using WFS-[topic-slug] format for consistency.
 -   **Coordination**: Session files coordinate with workflow-session.json and maintain document-state separation.