{
  "contract_version": "gab_202_contract_v1",
  "gab_id": "GAB-202",
  "canonical_name": "PlayEngineBlockStack",
  "module_owner": "EdTechPlayEngine",
  "renderer_key": "text_cta",
  "required_fields": [
    "gab_id",
    "block_stack_id",
    "blocks",
    "primary_cta"
  ],
  "optional_fields": [
    "title",
    "subtitle",
    "doctrine_note",
    "progress_label",
    "progress_pct",
    "renderer_key",
    "_note_dev"
  ],
  "field_types": {
    "block_stack_id": "string — identifiant unique de la pile",
    "blocks": "array<{num:number, label:string, module_type:enum['story','visual','interactive','exercise','memory','game','audio','leveltest'], module_label:string, ref:string, status:enum['completed','active','pending','error'], error_msg?:string}>",
    "primary_cta": "object{label:string, action:string}",
    "progress_pct": "number(0..100)",
    "progress_label": "string"
  },
  "constraints": [
    "blocks doit contenir au moins 1 élément — sinon BLOCKED.",
    "primary_cta.label : libellé du bouton, vient du JSON uniquement.",
    "status 'error' doit porter un error_msg explicite — jamais masquer l'erreur.",
    "PlayEngine orchestre les blocs mais ne possède pas la logique de chaque module_owner.",
    "Aucune écriture de XP/badge/coins dans ce gabarit — délégué à PlayKit."
  ],
  "blocked_conditions": [
    "gab_id absent",
    "block_stack_id absent",
    "blocks vides ou absent",
    "primary_cta absent"
  ],
  "accessibility": [
    "keyboard_navigable",
    "focus_visible",
    "prefers_reduced_motion",
    "fallback_text"
  ],
  "qa_cases": [
    { "case": "instance conforme", "expected": "rendu complet, 4 blocs affichés, 0 erreur moteur" },
    { "case": "champ requis manquant (block_stack_id absent)", "expected": "BLOCKED listant le champ" },
    { "case": "blocks:[] vide", "expected": "BLOCKED — blocks vides ou absent" },
    { "case": "bloc status:error sans error_msg", "expected": "bloc affiché en état error sans message (warning toléré)" },
    { "case": "instance externe injectée via ENGINE.init(ext)", "expected": "le rendu change sans modifier le HTML" },
    { "case": "responsive 375/768/1024", "expected": "aucun débordement horizontal" }
  ],
  "traceability": {
    "derived_from_core_gab": "GAB-202",
    "note": "Ce schema VALIDE l'instance. Le contrat pédagogique complet (input_contract/validation_logic/feedback_scoring_logic) vit dans le CORE-GAB officiel, pas ici (évite la duplication)."
  }
}