One engine · tabs are channels · doors are entry points · "apps" are modes — Build + SecJSON decide what shows.
SPEC_comm_mini_v1. The Call tab mounts the real
<gmad-phone> dialer. Use the controls to prove the model: switch tier and watch tabs/doors filter;
fire a mode (Phone/Radio/…); open a door from a circle member (contact-anchored — no blank call); start a call and minimize it (PiP) while you browse other tabs.
The Comm mini is a single phone-first column. On Tablet you'll see it stretch — that's the visual cue for where a tablet-specific layout (e.g. master/detail split: list on the left, thread/call on the right) would be added later. Phone is the primary target.
Tapping a person opens Comm pre-targeted to them with an action sheet (Call / Video / Message / Voicemail). A comm icon on a highlighted member does exactly this.
Message class: 💬 IM · ✉ DM · 🙈 SM secret · ⏳ XM expiring · 🔒 ZP encrypted | Transport: 🛡 private mesh · 🌐 public · 📡 radio. Members see the glyph, not the raw rail.