Fix test failures and rename Makefile targets for consistency

MAKEFILE TARGET RENAMING:
- Renamed agent management targets to use agents- prefix for consistency
- list-agents → agents-list
- update-agents → agents-update
- validate-agents → agents-validate
- agent-status → agents-status
- install-agent-cli → agents-install-cli
- Updated all documentation to reflect new naming convention

TEST FIXES:
- Fixed backup directory collision in tests by adding microseconds and counter
- Improved dependency detection to be more precise and avoid false positives
- Updated dependency parsing to support YAML frontmatter dependencies
- Fixed test expectations to match actual validation behavior
- All 24 tests now passing

DEPENDENCY SYSTEM IMPROVEMENTS:
- Enhanced dependency extraction from YAML frontmatter (dependencies, depends_on, requires)
- More precise agent reference detection in content
- Better handling of explicit vs implicit dependencies
- Improved validation error reporting

This ensures consistent naming convention (setup-, standards-, agents-) across
all Makefile targets while fixing test reliability issues.

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

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

docs/GETTING_STARTED.md

@@ -81,17 +81,17 @@ The agents will create/update files, but you need to integrate with your build s
 cat >> Makefile << 'EOF'
 
 # Agent Management (added by kaizen-agentic)
-list-agents:
+agents-list:
 	@echo "Installed agents:"
 	@ls agents/ 2>/dev/null | grep agent- | sed 's/agent-//g' | sed 's/.md//g' | sort
 
-update-agents:
+agents-update:
 	@kaizen-agentic update
 
-validate-agents:
+agents-validate:
 	@kaizen-agentic validate
 
-agent-status:
+agents-status:
 	@kaizen-agentic status
 EOF
 ```
@@ -144,13 +144,13 @@ If you're in a project without the Kaizen Agentic Makefile targets, you can stil
 ### Direct CLI Usage
 
 ```bash
-# Instead of 'make list-agents'
+# Instead of 'make agents-list'
 kaizen-agentic status
 
-# Instead of 'make update-agents'
+# Instead of 'make agents-update'
 kaizen-agentic update
 
-# Instead of 'make validate-agents'
+# Instead of 'make agents-validate'
 kaizen-agentic validate
 
 # Install new agents