feat(keyboard): hold-Enter accent popup; relocate cursor-mode trigger

Replaces the 8 separate Latin-diacritic alt-alphabet pages (Polish, Czech,
Slovak, German, French, Spanish, Portuguese, Nordic) with one popup: Hold
Enter on a Latin letter that has accented variants (a c d e i l n o r s
t u y z) opens a floating horizontal strip of that letter's accents,
anchored over its own row so the grid stays visible underneath (LEFT/
RIGHT picks, Enter inserts via a new shared insertGlyph() helper, Cancel
dismisses). Holding a letter with no variants is a no-op. Cyrillic/Greek
remain full alt-alphabet pages; NodePrefs::keyboard_alt_alphabet shrinks
from 11 to 3 values accordingly -- an old saved Polish..Nordic value just
clamps to Latin via DataStore.cpp's existing range check, no migration
code needed.

Freeing Hold-Enter on letter cells required moving cursor-mode's own
trigger: UP from the top letter row now enters it instead of wrapping to
the special row. To keep that wrap reachable, cursor mode's UP/DOWN
(Home/End) continue the wrap once already at that boundary -- UP again
lands on the special row, DOWN again back on the letter grid -- reusing
the same proportional column mapping the old direct wrap used.

Diagnostics' font-coverage sample swaps its 8 per-language lines for one
line sampling the new accent table. Docs (message_screen, settings_screen,
solo_ui_framework) and release-notes updated to match.

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

release-notes.md

@@ -6,7 +6,7 @@
 - **On-device channel management.** Messages › Channels gets a **"+ Add channel"** row and per-channel **Edit**/**Delete** — create or join a channel by typing either a passphrase (hashed to the channel secret, same idea as a room password) or the exact 32-hex-character key from a channel QR code. No phone app required.
 - **Tools › Admin — administer a remote repeater/room from the device.** Log into a node you have admin rights on (same self-healing saved-password handshake as room logins) and browse its settings in category tabs — **System** (name, owner info), **Radio** (Frequency/Bandwidth/Spreading factor/Coding rate/TX power), **Routing** (Repeat/Advert interval/Flood advert interval/Max hops), **Actions** (reboot, send advert, sync clock, …) — plus a free-text **Custom command…** escape hatch (with **{}**-key command-name completion) for anything not covered. Radio and Routing fields use a type-appropriate editor instead of raw text — a digit-cursor for Frequency (the same widget Settings' own Radio screen uses locally), discrete-set stepping for Bandwidth/Spreading factor/Coding rate, plain number steppers for the rest, and an ON/OFF toggle for Repeat — adjusting a value costs no mesh traffic until you actually confirm it with **Enter** (**Cancel** sends nothing). Reachable either from **Tools › Admin** (opens the same Nodes list to pick a target) or directly via a repeater/room's own **Hold Enter › Admin** action.
 - **Auto-Reply Bot gains a third target: room servers**, alongside DM and Channel, with its own trigger/reply/commands — the screen is redesigned as a circular tab carousel (**Direct/Channel/Room/Other**, **LEFT/RIGHT** to switch, **UP/DOWN** within a tab) instead of one long list. Each target's **Enable** and **Commands** toggle is now fully independent (they used to secretly share the DM tab's setting for Channel/Room too). New `{name}`/`{hops}` reply placeholders, a DM allow-list (all chat contacts or favourites only), and a dedicated stepper for Quiet Hours.
-- **Keyboard: more languages, better editing.** Eight more per-language keyboards — Polish, Czech, Slovak, German, French, Spanish, Portuguese, Nordic — join Cyrillic and Greek under **Settings › Keyboard › Alphabet**, each with a linguistically complete letter set in both the ABC grid and T9 multi-tap groups. Shift is now **one-shot** by default (capitalises just the next letter; **Hold Enter** on Shift toggles the old sticky caps-lock back on), **Hold Enter** on Backspace clears the whole field, and a new **Hold Enter** cursor-positioning mode (**LEFT/RIGHT** move, **UP/DOWN** jump to start/end) lets you edit or insert anywhere in what you've typed, not just at the end.
+- **Keyboard: accent popup, better editing.** Holding **Enter** on a Latin letter with accented variants (`a c d e i l n o r s t u y z`) now opens a one-row popup of that letter's accents — e.g. holding `a` offers `á à â ã ä å ą` — covering every European Latin-diacritic letter (Polish, Czech, Slovak, German, French, Spanish, Portuguese, Nordic, …) from one popup instead of a separate page per language; **Cyrillic**/**Greek** remain full alt-alphabet pages under **Settings › Keyboard › Alphabet**. Shift is now **one-shot** by default (capitalises just the next letter; **Hold Enter** on Shift toggles the old sticky caps-lock back on), **Hold Enter** on Backspace clears the whole field, and **UP** from the top letter row enters a cursor-positioning mode (**LEFT/RIGHT** move; **UP/DOWN** jump to start/end, then continue on to the special row / letter grid if pressed again once already there) so you can edit or insert anywhere in what you've typed, not just at the end.
 - **Messages get a messenger-style history.** History bubbles are now sized to their content and anchored **right** (outgoing) / **left** (incoming); the list runs **newest at the bottom**, growing upward as you scroll into the past; the **[+ send]** compose button moved to the right edge to match.
 - **Clock Tools: alarm repeat.** The Alarm screen gains a **Repeat** row (Off/Daily/Weekdays/Weekends) — Hour/Minute merge into one **Time** row edited with an HH:MM digit cursor, and **Repeat**/**Armed** now respond to **LEFT/RIGHT** like every other Settings field instead of Enter-only.
 - **Diagnostics becomes a tab carousel** (Live/System/Font): **System** adds firmware version + build date, device model and the active radio parameters; **Font** is a rendering test card with one sample line per script the on-device font covers, so coverage can be eyeballed directly.