docs: trim wording across README and solo_features docs

Cut restated points, hedge phrases and over-explained asides throughout
-- same information, fewer words per sentence. Also fixed a stale gap
in README's "Building from source" env table (Cardputer ADV and
T-Echo Lite + KeyShield were missing).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

docs/solo_features/message_screen/message_screen.md

@@ -23,7 +23,7 @@ Press **Enter** on a contact or channel to open its history, then press **Enter*
 - **Custom message** — opens the on-screen keyboard
 - **Q1–Q10** — quick reply templates editable in Settings › Messages
 
-While typing, **UP** from the top letter row enters cursor mode (LEFT/RIGHT move the insertion point; UP/DOWN jump to start/end, then continue on to the special row / letter grid if pressed again once already there; Enter/Cancel exit immediately from anywhere) so you can edit or insert in the middle of what you've typed instead of only at the end. **Hold Enter** on a Latin letter with accented variants (e.g. a, e, c, n, o, s, z…) instead opens a one-row popup of that letter's accents — LEFT/RIGHT to pick, Enter to insert, Cancel to dismiss. See the on-screen keyboard section of the [UI framework guide](../../design/solo_ui_framework.md) for the full key set (Shift, T9 multi-tap, Cyrillic/Greek).
+While typing, **UP** from the top letter row enters cursor mode — LEFT/RIGHT move the insertion point, UP/DOWN jump to start/end (then to the grid on a second press), Enter/Cancel exit from anywhere — so you can edit mid-text, not just at the end. **Hold Enter** on a letter with accented variants (a, e, c, n, o, s, z…) opens a one-row accent popup instead — LEFT/RIGHT picks, Enter inserts, Cancel dismisses. Full key set (Shift, T9, Cyrillic/Greek) in the [UI framework guide](../../design/solo_ui_framework.md).
 
 The keyboard supports placeholders that insert live data at send time:
 
@@ -44,12 +44,12 @@ Sensor placeholders appear automatically in the placeholder picker when the corr
 
 ### Rooms — logging in
 
-Posting to a **room server** requires a login handshake first, so the device can log in on its own — no phone app needed. The first time you press **Enter** on a room, a password prompt opens automatically; type the room's password and press the **✓** key (leave it empty and submit for open / no-password rooms). Once the login succeeds the room's chat **opens automatically** — no second Enter needed (as long as you're still on that room in the list).
+Posting to a **room server** needs a login handshake — the device does this on its own, no phone app needed. First **Enter** on a room opens a password prompt automatically; type it and press **✓** (empty for no-password rooms). On success the chat opens automatically, no second Enter needed.
 
-- **Passwords are remembered across reboots.** After a successful login the password is saved on the device, so picking that room again — even after a power cycle — logs back in silently and drops you straight into the chat.
-- **A wrong or changed password self-heals.** If a saved password stops working (e.g. the server's password was changed), the failed login forgets it, so the next **Enter** prompts you to type a new one.
-- **Re-login any time** with **Hold Enter** on the room → **Login…** (see the room context menu below) — useful to switch to a new password without waiting for a failure.
-- **Log out** with **Hold Enter** on a room you're currently logged into → **Logout** (only offered once logged in). Forgets the saved password on the device, so the next time you open that room it prompts for one again instead of silently reusing the old one.
+- **Passwords are remembered across reboots.** After a successful login it's saved on the device, so picking that room again — even after a power cycle — logs back in silently.
+- **A wrong or changed password self-heals.** A failed login forgets the saved password, so the next **Enter** prompts for a new one.
+- **Re-login any time** with **Hold Enter** on the room → **Login…** — useful to switch passwords without waiting for a failure.
+- **Log out** with **Hold Enter** → **Logout** (only offered once logged in). Forgets the saved password, so the next open prompts for one again.
 - Passwords set from the **phone app** are saved on the device too, so it can post to that room standalone after a reboot.
 
 > The on-screen keyboard's default (Latin) page is ASCII only. Typing accented or non-Latin characters — Polish, Czech, Slovak, German, French, Spanish, Portuguese or Nordic diacritics, Cyrillic, or Greek — needs Settings › Keyboard › Alphabet set to the matching language first; the keyboard's **#@/abc** key then cycles Latin → that alphabet → Symbols → Latin. A password containing characters outside whatever's currently enabled can still be set from the phone app — the device stores and replays it byte-for-byte.
@@ -62,7 +62,7 @@ Posting to a **room server** requires a login handshake first, so the device can
 | :-----------------------: | :-----------------------: |
 | ![](./history_oled.png) | ![](./history_eink.png) |
 
-Messages are drawn as chat bubbles sized to fit their content, anchored **right** for your own outgoing messages and **left** for incoming ones (like a typical messenger), with the sender name and a compact age indicator (`3m`, `2h`, `>1d`) in the top-right corner of each bubble. The list runs **newest at the bottom** — opening a history starts you at the latest message, and scrolling **up** goes further into the past.
+Messages appear as chat bubbles sized to their content — **right**-anchored for outgoing, **left** for incoming — with sender name and a compact age indicator (`3m`, `2h`, `>1d`) in the top-right corner. List runs **newest at the bottom**; opening a history starts at the latest message, scrolling up goes further back.
 
 **Short Enter** on a message opens it in fullscreen. **Hold Enter** — on a history row or in fullscreen — opens the same options menu: Reply, plus **Navigate** / **Save waypoint** when the message contains a location (see Fullscreen message view). You don't need to open the message first.
 
@@ -138,12 +138,12 @@ In the **Rooms** list the context menu instead offers:
 
 ### Adding / editing a channel
 
-Joining a new community channel, or creating one to share with others, no longer needs the phone app. The **Channels** list ends with a **"+ Add channel"** row — press **Enter** on it to pick a channel type, or use **Edit** from the context menu above to change an existing channel's name or secret (Edit skips the type picker and opens the Name/Secret form directly).
+Joining or creating a community channel no longer needs the phone app. The **Channels** list ends with **"+ Add channel"** — **Enter** picks a channel type; **Edit** from the context menu changes an existing channel's name/secret directly, skipping the type picker.
 
-**+ Add channel** first asks which type of channel to create — the same three types the phone app offers:
+**+ Add channel** first asks which type to create — the same three the phone app offers:
 
-- **Public** — instantly re-adds the well-known default public channel (no fields to fill in). Useful if it was deleted and you want it back without remembering its key.
-- **Hashtag** — type a topic name (e.g. `test`); the channel's name and secret are both derived from it (name becomes `#test`, secret is the first 16 bytes of `sha256("#test")`). A topic-based public group chat — anyone who types the same topic elsewhere ends up on the same channel — separate from the default Public channel.
+- **Public** — instantly re-adds the well-known default public channel, no fields needed. Useful if it was deleted and you don't remember its key.
+- **Hashtag** — type a topic (e.g. `test`); name (`#test`) and secret (first 16 bytes of `sha256("#test")`) are both derived from it. A topic-based public chat — anyone typing the same topic elsewhere lands on the same channel, separate from the default Public one.
 - **Private** — the manual Name + Secret form:
 
   | Field  | Notes                                                                                        |
@@ -151,10 +151,10 @@ Joining a new community channel, or creating one to share with others, no longer
   | Name   | Up to 31 characters                                                                            |
   | Secret | **LEFT/RIGHT** toggles between two entry modes; **Enter** opens the keyboard for whichever is selected |
 
-  - **Passphrase** (default) — type any text; the device hashes it down to the channel's 16-byte secret. Easiest to agree on verbally, the same idea as a room password — two people who type the same passphrase end up on the same channel.
-  - **Hex key** — type the exact 32-hex-character secret (the format used by channel QR codes, see [QR Codes](../../qr_codes.md)), for joining a channel whose precise secret you were given rather than agreeing on a new passphrase. An all-zero secret (`00…0`) is rejected ("Invalid secret") — that value is reserved internally to mark an empty channel slot.
+  - **Passphrase** (default) — type any text; the device hashes it to the channel's 16-byte secret. Easiest to agree on verbally — same idea as a room password.
+  - **Hex key** — the exact 32-hex-character secret (channel QR code format, see [QR Codes](../../qr_codes.md)), for joining with a secret you were given rather than a new passphrase. An all-zero secret (`00…0`) is rejected — reserved internally for an empty slot.
 
-  Select **[Save]** to commit. The secret can't be redisplayed once saved (only the derived key is kept) — editing it later means typing a new passphrase or hex key, the same as re-logging into a room with a new password.
+  Select **[Save]** to commit. The secret can't be redisplayed once saved (only the derived key is kept) — editing later means typing a new one, same as re-logging into a room.
 
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