Adds the behavioral matrix for a dedicated init.debug handler before the
handler exists: equivalence cross-checks against the three calls debug.md
makes today (state.load, resolve-model, config-get workflow.tdd_mode),
bundle shape, the CLI negative/hostile argv matrix, section_manifest
null-vs-[] degradation, planningPaths.debug, and a guard that
WHEN_VOCABULARY stays closed at 29 entries.
Currently RED: the init router reports "Unknown init workflow: debug".
Matrix: .gsd/phase/feat-3149-cmdinitdebug/50-test-matrix.md
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
