Test 2: Per-module synth baseline.
Runs mdaa synth for a single module and diffs the template against baseline
using CDK's semantic diff engine (same as module-level baselineDiffTestApp).
Integration entry point: composes unit-tested helpers (prepareKit, runMdaaCli,
findAssemblyDir, normalizeAssemblyTemplates, diffAssembly) and runs a real CDK
synth + toolkit diff. It is exercised end-to-end by each kit's *.diff.test.ts,
so the test()-registration body is excluded from unit coverage.
Test 2: Per-module synth baseline. Runs mdaa synth for a single module and diffs the template against baseline using CDK's semantic diff engine (same as module-level baselineDiffTestApp).
Integration entry point: composes unit-tested helpers (prepareKit, runMdaaCli, findAssemblyDir, normalizeAssemblyTemplates, diffAssembly) and runs a real CDK synth + toolkit diff. It is exercised end-to-end by each kit's *.diff.test.ts, so the test()-registration body is excluded from unit coverage.