fix(ui): confirm destructive actions, retire last Hold-Enter-cancel, de-dup labels

Continuing the consistency review: sweep for the same three defect shapes
elsewhere in ui-new/ (own read pass plus two parallel research agents),
verified against source before acting.

Three destructive actions fired on a single Enter with no way back, unlike
contact-delete's existing confirm-defaulted-to-Cancel popup: Trail's "Reset
trail" (wipes the whole recorded route, no undo short of a prior manual
Save -- reuses Trail's own multi-level menu machinery, alongside its
GPS-off confirm), Messages' channel Delete, and RadioPresetPicker's saved-
preset delete (shared by Settings > Radio and Tools > Repeater, so one fix
covers both). All three now confirm the same way, defaulting to Cancel.

KeyboardWidget was the one place Hold-Enter still doubled as Cancel: Shift,
Backspace and a Latin letter's accent popup already have real, kept
meanings under a hold, but every other special-row cell (Space, OK/Done,
the {} placeholder) fell through to a bare CANCELLED, closing the keyboard
exactly like the real Cancel key. Now a no-op there too, matching the "only
Back closes it" rule already applied to popups and screens.

MessagesScreen defined the same two label arrays (Notif states, melody
slots) four times over, once per context-menu handler. Hoisted to one
pair of static class members -- constexpr wasn't enough to get the linker
to emit them on this toolchain, so they follow the same declare-in-class/
define-out-of-class shape NearbyScreen::FILTER_LABELS already uses.

Alert text: "Advert sent!"/"Advert failed.." and "Sent!" were the only
toasts anywhere with trailing punctuation; normalized to the plain style
every other confirmation uses. Unpinning from the Favourites Dial reported
the freed slot number from the Messages screens but not from Nodes or the
dial's own tile menu; now consistent everywhere pinning already was.

DiagnosticsScreen's Live/System/Font tab renderers hand-rolled the same
scroll-clamp/loop/indicator skeleton drawList() already bundles; switched
both to drawList (passing the screen's own _scroll as its `sel` too, since
neither tab has a row cursor -- makes drawList's internal clamp a no-op and
leaves clampScroll() as the only thing bounding it, unchanged). Pure
internal tidy, no behavior change.

docs/solo_features/message_screen/message_screen.md

@@ -148,7 +148,7 @@ In the **Rooms** list the context menu instead offers:
 | Fav: ON / OFF             | Add or remove this channel from favourites — **LEFT/RIGHT** or **Enter** to toggle |
 | Pin to dial / Unpin (slot N) | Pin this channel to a [Favourites Dial](../favourites_dial/favourites_dial.md) slot |
 | Edit                      | Opens the Add/Edit form below, pre-filled with the channel's name    |
-| Delete                    | Removes the channel immediately (no confirm prompt)                   |
+| Delete                    | Removes the channel — confirms first (defaults to Cancel)             |
 
 ---
 

docs/solo_features/settings_screen/settings_screen.md

@@ -65,7 +65,7 @@ Lists all available home screen pages. For each entry:
 | Setting   | Options    | Notes                                                                                                                                                              |
 | --------- | ---------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
 | TX Pwr    | 2–22 dBm   | LEFT/RIGHT. With **Auto pwr** on this is the *ceiling* — the radio may transmit lower. |
-| Preset    | named presets | LEFT/RIGHT cycles community RF presets (region frequency + bandwidth/SF/CR). **Enter** opens a popup to pick one, save the current settings as a named preset, or delete a saved one. Applies frequency, bandwidth, SF and CR together. |
+| Preset    | named presets | LEFT/RIGHT cycles community RF presets (region frequency + bandwidth/SF/CR). **Enter** opens a popup to pick one, save the current settings as a named preset, or delete a saved one — deleting confirms first (defaults to Cancel). Applies frequency, bandwidth, SF and CR together. |
 | Freq      | chip range | **Enter** opens a digit-by-digit editor: LEFT/RIGHT moves between decimal places, UP/DOWN steps that digit. Bounds come from the radio chip's own validated range, so a value the radio would reject can't be entered. |
 | SF        | 5–12       | LEFT/RIGHT. Spreading factor. |
 | BW        | 7.8–500 kHz | LEFT/RIGHT cycles the standard LoRa bandwidths. |

docs/solo_features/tools_screen/tools_screen.md

@@ -123,7 +123,7 @@ Cycle views with **LEFT / RIGHT**:
 | Load trail     | Restore flash trail into RAM                    |
 | Export (live)  | Stream live RAM trail as GPX 1.1 over USB Serial |
 | Export (saved) | Stream saved flash trail as GPX 1.1 over USB Serial |
-| Reset trail    | Clear RAM ring and elapsed time                 |
+| Reset trail    | Clear RAM ring and elapsed time — confirms first (defaults to Cancel) since there's no way back short of a prior **Save trail** |
 
 **Settings…** (values cycle with **LEFT/RIGHT** or **Enter**; shown only where they apply):