- Notifications ✅ split: the Core decides *what* happened (`MessageArrived` with kind / DM sender / channel slot, `AdvertHeard`); the frontend decides *how* to show it (`showAlert`, `SoundNotifier`, vibration, LED, wake-on-message) — those are platform services.
- Trail ✅ `ui-core/TrailEngine.h` — store, sampling, auto-pause, low-battery auto-save, recording actions (start/stop, reset, save/load `/trail`) used by both frontends. GPS averaging for marks ✅ `ui-core/GpsAverager.h`. Track back ✅ `ui-core/TrackBack.h`.
`ui-core/SettingsSchema.h` holds three pages -- navigation (trail, live share, arrival alert, units), display & power (brightness, screen off, wake on message, battery shutdown, GPS power saving, time zone) and messages & contacts (DM resends, contact expiry, favourites first). An entry is a one-byte index by default, or a `values` table over a 1/2/4-byte field (seconds, millivolts, an hour offset, `{1, 0}` for a field stored inverted); side effects run through `UiCore` (`applyGpsInterval()`, `host()->applyDisplayPrefs()`). ui-lvgl renders each page; ui-new still uses its own screens. Radio settings are not schema rows (preset list, typed frequency, radio side effects): `ui-core/RadioControl.h` applies them (`applyParams`, `applyTxPower`, `applyApc`, presets = built-ins + user slots) for both ui-new's Settings > Radio and ui-lvgl's Radio screen. Channel management is `ui-core/ChannelControl.h` (`chanctl::`): add Public / Hashtag / Private (passphrase or 32-hex key), rename, delete, notifications / favourite / scope, and `onRemoved()` -- the cleanup of every channel-keyed pref, run by `UiCore::onChannelRemoved` whoever deleted the channel (this device or the app); contacts get the same through `UiCore::cleanupContactPrefs`. Favourites dial slots: `ui-core/Favourites.h` (`pinContact` / `pinChannel` move an entry that is already on another slot; the slot's name is `contactctl::favName`). The schema's display page also carries the lock screen (`auto_lock`) and the 12-hour clock, which ui-lvgl implements (a slide-to-unlock card after the screen turns off). Remote admin is `ui-core/AdminSession.h` (`UiCore::admin`): login with the saved password (forgotten on a wrong password or a silent timeout), CLI round trips with timeouts, the field table (`admin::`), typed values; results come out one at a time through `take()`. `UiCore` offers login answers and CLI replies to it first; only room logins it wasn't waiting for reach the frontend. ui-new's Tools > Admin and ui-lvgl's Admin screen are views over it. The bot's settings are a table too, `ui-core/BotConfig.h` (`botcfg::`: tabs, rows, the NodePrefs flag / text / hour behind each, reply placeholders); ui-new's Tools > Bot and ui-lvgl's Bot screen render it, the bot itself runs in MyMesh. Room servers: `ui-core/RoomSessions.h` (`UiCore::rooms`) keeps who is logged in this session, the one login in flight (with a timeout) and the saved passwords (saved on success, forgotten on failure); `open(contact)` says whether to go straight in, wait for a background login or ask for a password, and outcomes come out through `take()`. Per-contact helpers are `ui-core/ContactControl.h` (`contactctl::`: DM notification / melody overrides, favourite flag, the `@[name] ` reply prefix, splitting a room post into author and text, naming a message's path hops). ui-new's Messages and ui-lvgl's Chats / thread use both. Diagnostics rows are `ui-core/Diagnostics.h` (`diag::`: live counters, system card, font card, counter reset), shown by ui-new's Tools > Diagnostics and ui-lvgl's Settings > Diagnostics. Auto-advert is a schema row (`advert_auto_interval_sec`, sent by MyMesh); ui-new keeps its Tools > Auto-Advert screen over the same pref. The compass (ui-lvgl Home > Compass, ui-new Tools > Compass) reads `UiCore::course`.
- Fonts ✅ Noto Sans generated by `ui-lvgl/fonts/generate.sh` (lv_font_conv): European Latin (Latin-1, Extended-A/B), Greek, Cyrillic + supplement, typographic punctuation, currency, LVGL symbols; 12/14/16/20 px, clock 40 px digits only. On-screen keyboard (`ui-lvgl/Keyboard.h`), phone-style: one layout per script (Latin QWERTY / Cyrillic ЙЦУКЕН / Greek) chosen by the same `keyboard_main_alphabet` / `keyboard_alt_alphabet` prefs as `ui-new` (globe key switches), hold a key for its variants; compose limit counted in UTF-8 bytes. Long-press variants and UTF-8 case mapping are shared with `ui-new` in `ui-core/KeyboardData.h`.
- Simulator ✅: `SIM_UI=lvgl variants/sim/build_wasm.sh` builds the same `ui-lvgl` code for the browser (`SimLcdDisplay` in `variants/sim/SimDisplayDriver.h` blits LVGL's RGB565 flush to a 320×240 canvas; the `SIM_PLATFORM` branch of `ui-lvgl/LvglPort.h` feeds the mouse in as touch). LVGL comes from the L2 env's PlatformIO libdeps; its objects are cached in `web/build/obj_lvgl/`. `web/lvgl.html` runs it next to a `ui-new` peer on a direct link (buttons: advert, peer DM, peer → Public, the board button) and exposes `window.sim` (`tap`, `hold`, `touch`, `peerDM`, `peerChannel`) for headless checks.
1.**Skeleton** ✅. `examples/companion_radio/ui-core/` with `UiCore.h` (facade), `MessageHistory.h`, `DmUnreadTable.h`. Header-only for now, reached from `ui-new/UITask.cpp` by relative include, so none of the 66 variant `platformio.ini` files that build `ui-new` change. `UITask` heap-allocates one `UiCore` in `begin()` (before the screens, as `MessagesScreen` used to own the history on the heap); `MessagesScreen` binds to `core().history` by reference. When the Core grows real `.cpp` files, compile them through a unity `.cpp` inside each frontend directory.
2.**Engines, one per commit.** Clock tools ✅ (also introduced `ui-core/UiEvents.h`, the Core → frontend event queue; `UITask::tickCore()` runs `UiCore::loop()` and drains it) → ping ✅ → course-over-ground ✅ → live share ✅ → locator ✅ → trail ✅ → notifications ✅ (with step 3). `UITask` shrinks to screen management + drawing.
3.**Flip the interface** ✅. `UiCore` is `MyMesh::Listener`; `ui-new`'s `UITask` derives `UITaskBase` + `UiCoreHost` and is fed by events, drained at the start (mesh-originated) and end (engines) of its `loop()`. Mesh callbacks no longer touch the display or buzzer directly.
6. Contacts/Nearby, Admin, Bot logic extraction as the LVGL screens for them are built. Nearby ✅: `ui-core/NearbyModel.h` builds the list (contacts + live [LOC] shares + heard adverts, or scan results), filter and sort; `ui-new`'s `NearbyScreen` inherits it (entry array stays with the screen), `ui-lvgl` owns one for its Nearby list + node detail (Message, Ping, favourite, Add, Delete). Home became three tiles: Messages, Nearby, Settings.
