feat: Simplify agent architecture with test-fix workflow (v3.2.0)

Major architectural improvements:
- Simplify from 3 agents to 2 core agents
- Adopt "Tests Are the Review" philosophy
- Enhance test-gen as 4-phase orchestrator
- Simplify review.md following update-memory pattern

Agent Changes:
- NEW: @test-fix-agent - Execute tests, diagnose failures, fix code
- ENHANCED: @code-developer - Now writes implementation + tests together
- REMOVED: @code-review-agent, @code-review-test-agent

Task Type Updates:
- "test" → "test-gen" (generate tests)
- NEW: "test-fix" (execute and fix tests)

Workflow Improvements:
- test-gen.md: 4-phase orchestrator (context-gather → concept-enhanced → task-generate → execute)
- review.md: Simplified to optional specialized reviews (security, architecture, quality, action-items)
- All 16 files updated with new agent references

See CHANGELOG.md for full details.

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

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

.claude/commands/task/create.md

@@ -107,8 +107,9 @@ Tasks inherit from:
 Based on task type and title keywords:
 - **Build/Implement** → @code-developer
 - **Design/Plan** → @planning-agent
-- **Test/Validate** → @code-review-test-agent
-- **Review/Audit** → @review-agent`
+- **Test Generation** → @code-developer (type: "test-gen")
+- **Test Execution/Fix** → @test-fix-agent (type: "test-fix")
+- **Review/Audit** → @general-purpose (optional, only when explicitly requested)
 
 ## Validation Rules