bfa09b68be
Context: The gamebook engine had a single short demo. We want several long, text-only "livre dont vous etes le heros" adventures to play on the Freenove (and to exercise deeper branching). Approach: Author each as a standalone gamebook YAML in game/gamebooks/, using the navigable format (passages with screen/text, choices as label+goto; a choiceless passage is an ending that restarts on click). Changes: - game/gamebooks/tour_horloger.yaml: "La Tour de l'Horloger" (fantastique/temps) — 23 passages, 8 fins. - game/gamebooks/train_de_nuit.yaml: "Le Dernier Train de Nuit" (mystere/huis clos) — 19 passages, 7 fins. - game/gamebooks/ile_echos.yaml: "L'Ile aux Mille Echos" (aventure/survie) — 16 passages, 7 fins. Impact: Three richly branched stories ready to stage on the master SD with tools/gamebook/build_gamebook.py. Graphs validated: no broken gotos, every passage reachable, multiple endings each.