feat(ui-lvgl): roadmap stage 5 - screen PIN, live map tiles, OTA from GitHub releases

- Screen PIN (Settings > Display & power > Security): 4-8 digits in NVS,
  keypad on the lock card after every wake and on boot, 5 misses -> 30 s pause
- Live map tiles: missing tiles at the current zoom are fetched over the saved
  WiFi, written to the card and drawn; WiFi drops 30 s after leaving the map;
  "Live tiles" switch in Map tools
- Firmware update (Settings > System): checks the fork's latest release,
  streams the -ota.bin into the spare app slot over TLS verified with the
  Arduino 3.x CA bundle, checks image magic/chip id, restarts
- Release workflow publishes *_solo_lvgl envs (merged image + -ota.bin)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/development/l2-hardware-checklist.md

@@ -251,3 +251,29 @@ The speaker plays through the ES8311 codec (I2S MCLK 10 / BCK 11 / WS 12 / DOUT
 - [ ] Nearby header: back, title, advert (tower), map, sort, scan (refresh icon) -- nothing overlaps; advert popup sends Nearby only / Everyone and sets Auto-advert
 - [ ] Status bar, right to left next to the battery: Bluetooth (grey on, white with the app), GPS (grey searching, green fix), bell (alarm set), mute, then amber: auto-advert (tower), trail (route), live share (pin), repeater (loop), arrival alert (flag, with a target); each appears / disappears within a second of switching it
 - [ ] All icons at once still leave the clock readable on the left
+
+## Roadmap stage 5: screen PIN (2026-09-26)
+- [ ] Settings > Display & power > SECURITY > Screen PIN "Off"; tap → keypad; 1234 ✓, 1234 ✓ → toast "PIN set", row "On", list stays at the bottom
+- [ ] A different second entry → "Didn't match - new PIN again"; fewer than 4 digits + ✓ → "At least 4 digits"
+- [ ] Screen off (WAKE or timeout) and on → PIN card (clock, unread count, keypad) instead of the slider, even with "Lock screen" off
+- [ ] Right PIN unlocks as soon as the last digit is in; wrong one → "Wrong PIN - n tries left"; 5 misses → "Too many tries - wait 30 s" counting down, keys ignored meanwhile
+- [ ] USER button does nothing on the PIN card; a ringing alarm is still dismissed by the buttons
+- [ ] Reboot → PIN card straight after boot
+- [ ] Change PIN (row tap with a PIN set) works; "Remove" in the popup's header → "PIN removed", slider lock / no lock as before
+- [ ] PIN survives a reboot and a firmware update (NVS "mc_lock"), not stored in NodePrefs
+
+## Roadmap stage 5: live map tiles (2026-09-26)
+- [ ] Map > ☰ > MAP > "Live tiles" on by default; with WiFi on and a network saved, zoom into an area without tiles → pill "WiFi Connecting..." then "live n", tiles appear one by one, the "(map zN)" magnification goes away
+- [ ] The fetched tiles are on the card (/maps/z/x/y.png): reopen the map offline → still there
+- [ ] Leave the map: WiFi drops ~30 s later; back within 30 s → no reconnect
+- [ ] Live tiles off → nothing fetched, toast "Live tiles off"; on without a saved network → "Pick a WiFi network first"
+- [ ] WiFi off in Settings → no live fetching; an area download still works as before (and takes over from live tiles)
+- [ ] No SD card map folder at all + live tiles → the folder is created and the map fills in
+
+## Roadmap stage 5: firmware update (2026-09-26, Arduino 3.x build only)
+- [ ] Settings > SYSTEM > Firmware update shows the installed version; 2.0.17 build: "Not available in this build"
+- [ ] Check for update: connects WiFi, asks GitHub; before a release with an L2 image: "vX has no image for this device" (proves TLS + the API work)
+- [ ] With a release carrying solo-vX-Wio-Tracker-L2-ota.bin: "vX is available" + Install (size in MB); install shows progress, screen stays on, back is refused ("Updating - wait")
+- [ ] After "restarting..." the device boots the new version (Settings shows it); contacts, messages, settings, PIN and WiFi kept
+- [ ] Up to date → "Up to date - the latest release is vX"; WiFi off / no network / map download running → toasts instead
+- [ ] Wrong network in the middle (unplug router) → "Download stalled", old firmware still boots

docs/development/l2-roadmap.md

@@ -64,10 +64,21 @@ L1 splits its tools into many small screens because of the joystick and the
 
 ## 5. Security and internet
 
-- [ ] Screen-lock PIN.
-- [ ] Map tiles fetched live while online.
-- [ ] One-button OTA from GitHub Releases (release asset + partition layout
-      check).
+- [x] Screen-lock PIN: 4-8 digits in NVS (`lvport::loadPin`), asked on
+      every wake and after a reboot, 5 misses pause entry for 30 s;
+      Settings > Display & power > SECURITY.
+- [x] Map tiles fetched live while online: the map queues tiles it is
+      missing, `TileDownloader` fetches them one at a time over WiFi (connected
+      on the first miss, dropped 30 s after leaving the map) and saves them to
+      the card; Map > ☰ > Live tiles (NVS, on by default).
+- [x] One-button OTA from GitHub Releases: Settings > System > Firmware
+      update (`OtaScreen.h`). The latest release's `-Wio-Tracker-L2-ota.bin`
+      (app image; `build-solo-firmwares.yml` now publishes `*_solo_lvgl`) is
+      streamed over TLS verified with the framework's CA bundle into the idle
+      slot of `default_16MB.csv` (two 6.25 MB app slots, no layout change),
+      chip id checked, then restart. Arduino 3.x builds only.
+- [ ] Before the first release with L2: make the 3.x env the
+      `*_solo_lvgl` one (stage 2's last item), then test an update end to end.
 
 ## 6. Theme
 
@@ -79,3 +90,13 @@ L1 splits its tools into many small screens because of the joystick and the
 - [ ] Find out whether LVGL on every display variant gives consistency and a
       nicer look more easily. Adopt only if the result is better and every
       feature is kept (L1: 128×64 OLED, nRF52, RAM already 68% used).
+
+## Backlog (found along the way)
+
+- [ ] USB power detection: `WioTrackerL2Board::isExternalPowered()` reads
+      STATUS0 (0x40) bit 7 of the chip at I2C 0x22 and always gets 0 with
+      USB plugged in (0x40 reads 0x01). Needed for a charging indicator and
+      for skipping the low-battery shutdown on the cable. Find the right
+      chip / register (devices on the bus: 0x14, 0x18, 0x21, 0x22, 0x2c,
+      0x34, 0x48, 0x5d). Found 2026-09-26.
+