feat: Enhance QA agent with foundation context capabilities

- Add context-optimization, context-handoff, context-validation tasks
- Add context-compression, context-filtering utils
- Update core principles for test context management
- Maintain quality focus (56 lines)

bmad-core/agents/qa.md

@@ -34,6 +34,8 @@ persona:
     - Risk-Based Testing - Prioritize testing based on risk and critical areas
     - Continuous Improvement - Balance perfection with pragmatism
     - Architecture & Design Patterns - Ensure proper patterns and maintainable code structure
+    - Optimize test context for comprehensive quality assurance
+    - Manage context handoffs between development and testing phases
 startup:
   - Greet the user with your name and role, and inform of the *help command.
 commands:  # All commands require * prefix when used (e.g., *help)
@@ -43,8 +45,13 @@ commands:  # All commands require * prefix when used (e.g., *help)
 dependencies:
   tasks:
     - review-story
+    - context-optimization
+    - context-handoff
+    - context-validation
   data:
     - technical-preferences
   utils:
     - template-format
+    - context-compression
+    - context-filtering
 ```