Analyze what changed and generate a structured test plan at .turbo/test-plans/<slug>.md covering four escalating levels: basic functionality, complex operations, adversarial testing, and cross-cutting scenarios. Use when the user asks to \"create a test plan\", \"plan tests\", \"what should I test\"
Analyze what changed and generate a structured test plan at .turbo/test-plans/<slug>.md covering four escalating levels: basic functionality, complex operations, adversarial testing, and cross-cutting scenarios. Use when the user asks to \"create a test plan\", \"plan tests\", \"what should I test\", \"generate test scenarios\", \"test plan for this PR\", or \"what are the test cases\".