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/messages.md

@@ -0,0 +1,117 @@
+# Messages
+
+Messages holds three lists: **Channels**, **Direct** messages and **Rooms**.
+Unread counts show on each conversation, on the list and on the home screen.
+
+> [!NOTE]
+> **Wio Tracker L2:** one screen with all three as sections; tap a section
+> title to fold it. **New** in the header starts a conversation with any
+> contact.
+
+## Reading
+
+Open a conversation to see its history as chat bubbles: yours on the right,
+received ones on the left, newest at the bottom. Each bubble shows the sender,
+its age and a small hop count: on a received message, how many repeaters it
+came through; on your own, how many repeaters were heard passing it on.
+
+**Enter** on a message opens it full screen; **Left / Right** there pages to the
+older and newer one.
+
+**Hold Enter** on a message for its options:
+
+- **Reply**: starts a message addressed to the sender (`@[name]`).
+- **Navigate**, **Save waypoint**, **Set as target**: when the message
+  contains a location (see [Navigation](./navigation.md)).
+- **Path** on a received message: the repeaters it came through.
+  **Relayed by** on your own channel post: the repeaters heard repeating it.
+
+> [!NOTE]
+> **Wio Tracker L2:** hold a bubble. The card shows when it was sent, the hop
+> count, the path as a diagram, and **Reply** / **Set target**.
+
+### How much is kept
+
+The device keeps the newest 48 channel messages and 32 direct messages, all
+conversations together. When a busy conversation pushes out messages you
+haven't read, its unread count gets a **+** (for example `48+`).
+
+> [!NOTE]
+> **Wio Tracker L2:** 256 channel and 128 direct messages in memory, and with
+> an SD card every conversation is also saved to the card (100 to 2000
+> messages each, Settings › Storage). The history survives a reboot and
+> scrolls back through everything on the card.
+
+## Writing
+
+Open a conversation and choose **[+ send]** (or Enter at the bottom of the
+history). Pick a quick message or **Custom message** for the keyboard.
+
+- **Quick messages**: ten of your own, edited in Settings › Messages.
+- **Placeholders** fill in live data when the message is sent:
+  `{loc}` (your GPS position), `{time}`, `{batt}`, and the readings of any
+  sensor the device has: `{temp}`, `{hum}`, `{pres}`, `{alt}`, `{lux}`,
+  `{dist}`, `{co2}`.
+
+> [!NOTE]
+> **Wio Tracker L2:** the compose bar sits under the conversation; its **+**
+> opens quick messages and placeholders. Quick messages are edited in
+> Settings › Messages & contacts.
+
+### The keyboard
+
+The on-screen keyboard is a letter grid (or a phone-style T9 keypad, Settings ›
+Keyboard › Layout). Up from the top row moves the cursor through the text.
+
+Accented letters don't need a language setting: **hold Enter** on the base
+letter and pick from its variants, for example `a` → `á à â ä å ą…`, `z` →
+`ź ż ž`. This covers Polish, Czech, German, French, Spanish, Nordic and the
+other European languages written in Latin.
+
+Settings › Keyboard picks two scripts, **Main** and **Additional**, from Latin,
+Cyrillic and Greek; the keyboard's **#@/abc** key cycles between them and
+symbols. Cyrillic includes the Ukrainian, Belarusian and Serbian letters
+(under the key they sit on). Received messages in any of these scripts display
+correctly whatever the keyboard is set to.
+
+> [!NOTE]
+> **Wio Tracker L2:** a phone-style keyboard. Hold a key for its accents; the
+> globe key switches between the two alphabets.
+
+## Channels
+
+**Hold Enter** on a channel for its options:
+
+| Option | Does |
+| ------ | ---- |
+| Mark all read | Clears its unread count |
+| Notif, Melody | Its own notification and sound, instead of the global ones |
+| Fav | Marks it as a favourite (shared with the app) |
+| Scope | The region its messages are tagged with (`*` = none); the list is in Settings › Radio › Scope |
+| Pin to dial | Puts it on the Favourites page |
+| Edit, Delete | Renames it or changes its secret; removes it |
+
+**+ Add channel** at the end of the list adds:
+
+- **Public**: the default public channel, if you deleted it.
+- **Hashtag**: a topic such as `#hiking`. Anyone who types the same topic
+  joins the same channel.
+- **Private**: a name and a secret, typed as a passphrase or as the 32-digit
+  hex key (the format of channel QR codes).
+
+> [!NOTE]
+> **Wio Tracker L2:** hold a channel, or tap ⚙ in an open channel, for its
+> options.
+
+## Direct messages
+
+**Hold Enter** on a contact: Mark as read, Notif, Melody, Fav, Pin to dial.
+**Fav** is the star shared with the app and sorts favourites to the top;
+**Pin to dial** only puts the contact on the Favourites page.
+
+## Rooms
+
+Opening a room logs in first. You type the password once (empty if the room
+has none); it's saved on the device, including passwords set from the app,
+so the next time it logs in without asking. A wrong password is forgotten and
+you're asked again. **Hold Enter** on a room offers **Login…** and **Logout**.