feat: enhance QA agent as senior developer with code review capabilities and major brownfield improvements

This release introduces significant enhancements across multiple areas:

QA Agent Transformation:
- Transform QA agent into senior developer role with active code refactoring abilities
- Add review-story task enabling QA to review, refactor, and improve code directly
- Integrate QA review step into standard development workflow (SM → Dev → QA)
- QA can fix small issues directly and leave checklist for remaining items
- Updated dev agent to maintain File List for QA review focus

Knowledge Base Improvements:
- Add extensive brownfield development documentation and best practices
- Clarify Web UI vs IDE usage with cost optimization strategies
- Document PRD-first approach for large codebases/monorepos
- Add comprehensive expansion packs explanation
- Update IDE workflow to include QA review step
- Clarify agent usage (bmad-master vs specialized agents)

Brownfield Enhancements:
- Create comprehensive Working in the Brownfield guide
- Add document-project task to analyst agent capabilities
- Implement PRD-first workflow option for focused documentation
- Transform document-project to create practical brownfield architecture docs
- Document technical debt, workarounds, and real-world constraints
- Reference actual files instead of duplicating content
- Add impact analysis when PRD is provided

Documentation Task Improvements:
- Simplify to always create ONE unified architecture document
- Add deep codebase analysis phase with targeted questions
- Focus on documenting reality including technical debt
- Include Quick Reference section with key file paths
- Add practical sections: useful commands, debugging tips, known issues

Workflow Updates:
- Update all 6 workflow files with detailed IDE transition instructions
- Add clear SM → Dev → QA → Dev cycle explanation
- Emphasize Gemini Web for brownfield analysis (1M+ context advantage)
- Support both PRD-first and document-first approaches

This release significantly improves the brownfield development experience and introduces a powerful shift-left QA approach with senior developer mentoring.

README.md

@@ -188,14 +188,14 @@ The reason #2 and 3 are optional is because now BMad V4 makes sharding optional
 
 This configuration file tells BMAD agents exactly where to find your project documents and how they're structured. It's the key to V4's flexibility and backwards compatibility.
 
-#### Key Features:
+#### Key Features
 
 - **Version Awareness**: Agents understand if your PRD/Architecture follows V4 conventions or earlier versions
 - **Flexible Document Locations**: Works whether your epics are embedded in PRD or properly sharded
 - **Developer Context**: Define which files the dev agent should always load
 - **Debug Support**: Built-in logging for troubleshooting story implementation
 
-#### Why It Matters:
+#### Why It Matters
 
 - **Use BMAD with ANY project structure** - V3, V4, or custom layouts
 - **No forced migrations** - Keep your existing document organization
@@ -363,6 +363,7 @@ npm install
 ### Workflow Guides
 
 - 📚 [Universal BMAD Workflow Guide](docs/bmad-workflow-guide.md) - Core workflow that applies to all IDEs
+- 🏗️ [Working in the Brownfield Guide](docs/working-in-the-brownfield.md) - Complete guide for enhancing existing projects
 - 🎯 [Cursor Guide](docs/cursor-guide.md) - Complete workflow for Cursor users
 - 🤖 [Claude Code Guide](docs/claude-code-guide.md) - Complete workflow for Claude Code users
 - 🌊 [Windsurf Guide](docs/windsurf-guide.md) - Complete workflow for Windsurf users