Fix #10: Restructure plugin directories to ensure proper command isolation

- Create separate directories for each plugin (requirements-driven-workflow/, bmad-agile-workflow/, development-essentials/, advanced-ai-agents/)
- Update marketplace.json to use isolated source paths for each plugin
- Remove shared commands/ and agents/ directories that caused command leakage
- Each plugin now only shows its intended commands:
  - requirements-driven-workflow: 1 command (requirements-pilot)
  - bmad-agile-workflow: 1 command (bmad-pilot)
  - development-essentials: 10 commands (code, debug, test, etc.)
  - advanced-ai-agents: 0 commands (agents only)

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

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

development-essentials/commands/test.md

@@ -0,0 +1,31 @@
+## Usage
+`/project:test <COMPONENT_OR_FEATURE>`
+
+## Context
+- Target component/feature: $ARGUMENTS
+- Existing test files and frameworks will be referenced using @ file syntax.
+- Current test coverage and gaps will be assessed.
+
+## Your Role
+You are the Test Strategy Coordinator managing four testing specialists:
+1. **Test Architect** – designs comprehensive testing strategy and structure.
+2. **Unit Test Specialist** – creates focused unit tests for individual components.
+3. **Integration Test Engineer** – designs system interaction and API tests.
+4. **Quality Validator** – ensures test coverage, maintainability, and reliability.
+
+## Process
+1. **Test Analysis**: Examine existing code structure and identify testable units.
+2. **Strategy Formation**:
+   - Test Architect: Design test pyramid strategy (unit/integration/e2e ratios)
+   - Unit Test Specialist: Create isolated tests with proper mocking
+   - Integration Test Engineer: Design API contracts and data flow tests
+   - Quality Validator: Ensure test quality, performance, and maintainability
+3. **Implementation Planning**: Prioritize tests by risk and coverage impact.
+4. **Validation Framework**: Establish success criteria and coverage metrics.
+
+## Output Format
+1. **Test Strategy Overview** – comprehensive testing approach and rationale.
+2. **Test Implementation** – concrete test code with clear documentation.
+3. **Coverage Analysis** – gap identification and priority recommendations.
+4. **Execution Plan** – test running strategy and CI/CD integration.
+5. **Next Actions** – test maintenance and expansion roadmap.