docs: stage I3 -- documentation rewritten under docs/solo

Short pages by feature (getting started, messages, contacts, navigation,
tools, settings, lock, hardware) instead of one page per OLED screen, with
Wio Tracker L2 differences as notes; facts checked against the code
(keyboard scripts vs. hold-for-accents, {batt}/{dist}, L2 limits and
settings layout). Developer guides and build flags under docs/solo/developer.
Old docs/solo_features and its ~50 screenshots removed; a hero banner and
three simulator screenshots added; links updated.

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

docs/solo/navigation.md

@@ -0,0 +1,125 @@
+# Navigation
+
+Everything here works from the device's own GPS; no magnetometer or extra
+hardware is needed. Distances and speeds follow Settings › System › Units
+(metric or imperial).
+
+## Trail
+
+**Tools › Trail** records your route in the background while you use the rest
+of the device (a blinking **G** in the status bar). Straight stretches are
+stored as their two ends, so the 512 points cover a long route. **Left / Right**
+switches between the **Summary** (distance, time, speed or pace), the **Map**
+(your route, waypoints, people sharing their position, the target) and the
+point **List**.
+
+**Hold Enter** for the trail menu: start / stop, mark a waypoint, the waypoint
+list, **Track back** (retrace the route to where it started), share your
+position, the trail file, and the trail settings:
+
+- **Min dist**: how far apart points are recorded.
+- **Auto-pause**: pauses the trail after you stop for 1–5 minutes and resumes
+  when you move, so breaks don't count.
+- **Mark avg**: averages the GPS for 5–30 seconds when marking a waypoint.
+- **Auto-save**: saves the trail when the device powers off, including a
+  low-battery shutdown.
+
+The trail lives in memory: save it (Trail file › Save) or turn on Auto-save
+to keep it through a reboot.
+
+### GPX export
+
+Connect USB, open [Solo Tools](https://marekzegare4.github.io/Solo-tools/) in
+Chrome or Edge and click **Connect device**, then on the device choose
+**Trail file › Export**. The GPX includes your waypoints. Without a browser,
+`uv run tools/trail_export.py` does the same. Disconnect the phone app first if
+it's connected over USB.
+
+> [!NOTE]
+> **Wio Tracker L2:** the trail holds 4096 points and is drawn on the map.
+> Its controls (start / stop, save, load, track back, reset) are in the map's
+> **Map tools**, the settings in Settings › Map. **GPX** writes the trail to
+> the SD card; take it off with the card as a USB drive
+> ([Hardware](./hardware.md)).
+
+## Waypoints
+
+A waypoint is a saved spot (the car, a camp, water) with a short label, up to
+16 of them, kept through reboots. Add one with **Mark here** at your position,
+or **+ Add by coords** to type coordinates. The list starts with **Trail
+start**, so you can always go back to where the trail began.
+
+**Hold Enter** on a waypoint: Rename, Delete, **Send** (as a message to a
+contact or channel) and **Set as target**.
+
+> [!NOTE]
+> **Wio Tracker L2:** up to 64 waypoints. The pin button on the map opens the
+> list; hold a spot on the map to make it a waypoint or the target.
+
+## Navigating to something
+
+**Navigate** on a waypoint, a node in Nearby or a location in a message opens
+the navigation view: the distance, the bearing **To** the target and your own
+heading (**Hdg**), with the time to arrival once you're getting closer. Turn
+until the two bearings match. The heading comes from your movement, so it
+shows `--` while you stand still.
+
+**Tools › Compass** shows the same heading as a scrolling tape with the
+degrees and direction.
+
+> [!NOTE]
+> **Wio Tracker L2:** the target is drawn on the map with a line to it, and a
+> bar with distance, bearing, heading and time to arrival. The Compass app is
+> a turning dial.
+
+## Sharing locations
+
+- **Once**: **Share my pos** in the trail menu sends your position to a
+  contact or channel you pick.
+- **A waypoint**: **Send** in the waypoint menu.
+- **Live**: **Tools › Live Share** sends your position while you move, to one
+  contact or channel, for 1 to 12 hours. It only sends after you've moved
+  (50–500 m) and never more often than you set; an optional heartbeat repeats
+  it while you stand still.
+
+With **Track loc** on in Live Share, other people's shares show on the map
+and in Nearby, with live distance and bearing.
+
+Locations travel as ordinary text (`[LOC]lat,lon`, or `[WAY]lat,lon label`
+for a waypoint), readable in the phone app and on other firmware. On the
+receiving side, **hold Enter** on the message to navigate to it, save it or
+set it as the target.
+
+## Locator
+
+**Tools › Locator** alerts you when you cross a circle around a target:
+arriving at a waypoint, leaving it, or a person coming near or moving away.
+
+- **Target**: a waypoint (a fixed place) or a contact (follows their live
+  share, else their last known position).
+- **Radius**: 50 m to 1 km.
+- **Mode**: alert on arriving, leaving, or both.
+- **Beeper**: ticks faster as you get closer, even when the sound is muted.
+
+**Set as target** in Nearby, the waypoint list or a message sets the target
+in one step. The target shows as a flag on the map.
+
+## Map
+
+The **Map** home page shows your position, the trail, waypoints, people
+sharing their position and the target. **Enter** opens the trail map;
+**hold Enter** shares your position.
+
+> [!NOTE]
+> **Wio Tracker L2:** a real map with offline tiles on the SD card. Drag to
+> pan, +/− to zoom, the crosshair follows your GPS again.
+>
+> - **Download**: frame an area on the map and download its tiles over WiFi.
+>   Downloaded areas can be renamed, refreshed or deleted.
+> - **Live tiles**: with WiFi on, tiles for where you look are fetched and
+>   cached, up to the size set in Settings › Storage.
+> - **Vector regions**: whole regions as packs made with
+>   `tools/maps/osm_vector.py`, copied to the card.
+>
+> The minimap on the home screen shows your surroundings at a glance; tap it
+> for the full map. The **Nodes** map shows every node with a position.