b203f0e4de
Escape-room mechanic: the retro phone can call the players on its own and tell them a story when they pick up. Approach: a story_ring_task rings at a random 15-30 min interval (only when the line is idle and a story pack is on the SD). Picking up routes through enter_story_from_ring(), which silences the bell and launches a random story via plip_gamebook_begin_random() straight into the gamebook state — no menu. If nobody answers within 1 min the bell stops and the next ring is rescheduled; hanging up mid-ring also silences it. The whole feature is gated behind CONFIG_PLIP_AUTO_RING (default n), so the phone stays silent unless explicitly enabled in menuconfig. The hook pickup paths (raw SLIC poll + debounced edge) mirror the existing NPC incoming-call handling, which is unreliable while the bell rings.