feat(route): path editor with out-and-back trace and a kept route; map markers as one drawn layer

Core: PathEditor (UiCore::route) loads, edits, traces and saves the route to
a contact; MyMesh::sendTrace over an explicit route with per-hop SNRs,
setContactPath / setContactPinned. A route can be kept
(CONTACT_FLAG_ROUTE_PINNED, ContactInfo::flags bit 4): a path heard from the
node doesn't replace it and the last DM resend doesn't drop it.

ui-lvgl: Route screen (node detail), repeater picker by distance, picking
hops by tapping the nodes map (numbered badges, line, Undo / Done). The
map's markers are one drawn layer with hit-testing and name decluttering
instead of three objects per node.

ui-new: Path / trace view in the Nodes action menu; Add reuses the list
filtered to repeaters.

First cut: built for L2 LVGL, L1 OLED and L1 e-ink, tried on L2 only.

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

docs/solo/developer/ui-core.md

@@ -150,6 +150,7 @@ consumes keys only.
 - 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.
 - Map (in progress): offline Web-Mercator raster tiles on the microSD (`/maps/{z}/{x}/{y}.png`, the Meshtastic MUI layout; optional per-column `.pak` from PR #3381's packer), SDMMC 1-bit mount in `LvglPort.h`. `ui-lvgl/map/TileProvider.h` is the swap point: the screen and `map/TileCache.h` (24 decoded RGB565 tiles in PSRAM, LRU) only call `renderTile(z, x, y, rgb565)`, so a vector renderer can replace the PNG provider later. `MapScreen.h`: pan by drag, +/-, re-centre/follow GPS, Nearby nodes with a position as markers (tap = node detail), one tile decoded per loop pass, never during a drag (the view fills in once the finger rests; an idle map decodes the ring around the view ahead, and a not-yet-decoded tile shows a cached coarser one meanwhile). `maps/attribution.txt` is behind a "©" on the map and in Settings > About. Two maps over the same tile view: Nearby's header opens the Nodes map (every node Nearby knows a position for), Home > Map the Navigation map (`NavMap.h`): saved waypoints, live shares, the recorded trail and the Locator target with a dashed line to it and a bar with distance / bearing / own course / ETA (`ui-core/EtaTracker.h`, shared with ui-new's NavView). Hold the map to drop a waypoint, the pin marks the GPS position; the bar opens the target list and the waypoint menu (go, rename, share as `[WAY]` into a conversation, delete). Node detail has Navigate (target followed by key); a person sharing on a channel is followed by sender name (Locator target kind 2). Settings > Navigation carries the `track_shared_loc` / `locator_enabled` switches ui-new has on its Live share / Locator screens. Tiles come from `tools/maps/fetch_tiles.py` (no default server: tile.openstreetmap.org blocks offline use) or on the device: the map's download button fetches the visible area (a few overview levels up to a chosen zoom) over WiFi (`map/TileDownloader.h`; skips tiles on the card, rejects non-PNG and placeholder answers; server from `maps/source.txt`, default OpenTopoMap). The HTTP GET runs on a worker task (`LvglPort.h`, keep-alive TLS); WiFi credentials (Settings > WiFi, with scan) live in NVS, and WiFi is on only during a download. The job (area + zoom range) stays in `maps/.job` until it completes, so a download cut short by power-off, lost WiFi or Stop is offered for Resume (tiles already on the card are skipped). Past the downloaded detail the map magnifies the nearest coarser tile it has (up to 2 levels -- more is just big pixels; zoom pill shows e.g. `z17 (map z15)`); known-missing tiles are remembered without a pixel buffer. Internal RAM is the constraint (Arduino-ESP32 2.0.17 / IDF 4.4: task stacks and, by default, mbedTLS buffers must be internal): with WiFi + Bluedroid up only ~13 KB was left, so the L2 LVGL env sets `MESH_IN_PSRAM` (`the_mesh`, ~120 KB, placement-new into PSRAM in `main.cpp`) and the fetch task points mbedTLS at PSRAM. The download popup shows IP, RSSI, free/largest internal heap and the last TLS/HTTP error. Arduino-ESP32 3.x (IDF 5: PSRAM stacks, NimBLE) is to be evaluated in the polishing phase. In the simulator the same code downloads through emscripten fetch.
+- Route and trace ✅ (built, not yet tested on hardware): `ui-core/PathEditor.h` (`UiCore::route`) holds the repeaters between this node and a contact -- loaded from the contact's stored path, edited (add / move / remove), traced and saved (`MyMesh::setContactPath`). A trace goes out and back (A B dest B A) over `MyMesh::sendTrace`, because the reply only arrives if the last retransmission is heard; `PingEngine::startTrace` keeps the SNR of every hop (`PingResult::snrs_x4`, up to `TRACE_SNR_MAX`). Views: ui-lvgl's Route screen (node detail > Route and trace; `RouteScreen.h`) with a picker by distance and "Map" -- the nodes map where tapping repeaters in order builds the route (numbered badges, a line); ui-new's Path view (`RouteView` in `NearbyScreen.h`, the node's action menu > Path / trace) with Add handing the Nodes list over filtered to repeaters. A saved route can be kept (`CONTACT_FLAG_ROUTE_PINNED`, `ContactInfo::flags` bit 4; "Keep" in both views): `MyMesh::onContactPathRecv` puts the held path back after the base class took a heard one, and `tickDmResends` doesn't drop it before the last resend; Reset path (device or app) clears the flag. The ui-lvgl map's markers are one drawn layer (`mapview::drawMarks`, hit-tested by `hitMark`), not an object each.
 - PR #3381's LVGL UI is a reference for platform glue (flush, GT911, PSRAM pool) only; its screens are not adopted.
 
 ## Migration plan