feat: transform QA agent into Test Architect with advanced quality capabilities

- Add 6 specialized quality assessment commands
  - Implement risk-based testing with scoring
  - Create quality gate system with deterministic decisions
  - Add comprehensive test design and NFR validation
  - Update documentation with stage-based workflow integration

expansion-packs/bmad-2d-unity-game-dev/data/development-guidelines.md

@@ -531,25 +531,21 @@ Assets/
 ### Story Implementation Process
 
 1. **Read Story Requirements:**
-
    - Understand acceptance criteria
    - Identify technical requirements
    - Review performance constraints
 
 2. **Plan Implementation:**
-
    - Identify files to create/modify
    - Consider Unity's component-based architecture
    - Plan testing approach
 
 3. **Implement Feature:**
-
    - Write clean C# code following all guidelines
    - Use established patterns
    - Maintain stable FPS performance
 
 4. **Test Implementation:**
-
    - Write edit mode tests for game logic
    - Write play mode tests for integration testing
    - Test cross-platform functionality