UOW-005: Fix Failing Template Registry Test

[andhijeannot]

Overview

Phase: 2 - Code Quality
Priority: High
Estimated Effort: 4-6 hours

Problem Description

The failing test TestNewCmdWithExistingTemplate indicates registry state management issues and test isolation problems.

Acceptance Criteria

• All failing tests pass consistently
• Tests are properly isolated from each other
• Registry state is correctly managed in tests
• Test setup and teardown procedures are robust
• No flaky test behavior

Files to Modify

• cmd/new_test.go (major refactoring)
• internal/testutil/testutil.go (new file)
• internal/registry/registry_test.go (review and fix)

See roadmap/phase2-quality/UOW-005-fix-failing-tests.md for detailed implementation plan.