feat(ui): CardKB (I2C keyboard) support with full keyboard-only navigation

Auto-detected at boot on Wire1/Grove (addr 0x5F) -- no setting to flip, and a
no-op on boards without that bus or with nothing attached. This UI's key
codes (KEY_LEFT/UP/DOWN/RIGHT/ENTER/CANCEL) already match CardKB's own byte
protocol, so most input needs zero translation and flows through the same
key queue as physical buttons.

Two bytes get remapped in UITask::pollCardKB():
- Enter, only when the on-screen keyboard's plain grid state is active (no
  placeholder/accent popup, not in cursor-mode), becomes a new KEY_KB_ENTER
  sentinel meaning "submit the field" -- reusing plain KEY_ENTER there would
  insert a stray character, since a CardKB typist's row/col never reflect an
  intentional grid selection. Everywhere else Enter is untouched, so
  selecting a placeholder or committing an accent still works normally.
- Tab (otherwise unused) becomes KEY_CONTEXT_MENU, standing in for the
  "Hold-Enter" long-press gesture CardKB has no way to produce -- without it,
  ~30 context menus across the UI (message reply/navigate, Bot/Admin/
  Repeater, ...) would be unreachable from the keyboard alone.

KeyboardWidget gains a direct-typing path: printable ASCII inserts straight
at the cursor bypassing the grid, Backspace deletes, KEY_KB_ENTER submits.

Build-verified: WioTrackerL1_companion_solo_dual and
WioTrackerL1Eink_companion_solo_dual both compile and link clean; also
smoke-tested Heltec_mesh_solar_companion_radio_ble (no ENV_PIN_SDA/SCL) to
confirm zero regression on boards without the feature.

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

examples/companion_radio/ui-new/KeyboardWidget.h

@@ -721,6 +721,30 @@ struct KeyboardWidget {
 
     if (c == KEY_CANCEL) return CANCELLED;
 
+    // Direct-typing passthrough (CardKB or similar literal-ASCII input
+    // source, see UITask::pollCardKB()). Printable characters insert
+    // straight at the cursor, bypassing the on-screen grid entirely -- no
+    // caps re-application, the source already sends the correct case.
+    // Backspace deletes the previous character. KEY_KB_ENTER (only ever
+    // emitted when the grid is in this exact plain state -- no popup, no
+    // cursor-mode, see pollCardKB()) submits the field, instead of
+    // KEY_ENTER's usual "commit grid cell (row,col)".
+    if (c == KEY_KB_ENTER) return DONE;
+    if (c == 0x08) {
+      if (cursor_pos > 0) {
+        int n = kbUtf8LastCharBytes(buf, cursor_pos);
+        memmove(buf + cursor_pos - n, buf + cursor_pos, len - cursor_pos);
+        len -= n; cursor_pos -= n;
+        buf[len] = '\0';
+      }
+      return NONE;
+    }
+    if (c >= 0x20 && c <= 0x7E) {
+      char one[2] = { c, '\0' };
+      insertGlyph(one, false);
+      return NONE;
+    }
+
     const int rows = gridRows();
     const int cols = gridCols();
 

examples/companion_radio/ui-new/UITask.cpp

@@ -1386,6 +1386,13 @@ void UITask::begin(DisplayDriver* display, SensorManager* sensors, NodePrefs* no
   uint32_t aoff = autoOffMillis();
   _auto_off = millis() + (aoff > 0 ? aoff : AUTO_OFF_MILLIS);
 
+#if defined(ENV_PIN_SDA) && defined(ENV_PIN_SCL)
+  // Wire1 is already brought up by sensors.begin() (EnvironmentSensorManager),
+  // which runs before this -- just probe for a CardKB sitting on it.
+  Wire1.beginTransmission(0x5F);
+  _has_cardkb = (Wire1.endTransmission() == 0);
+#endif
+
 #if defined(PIN_USER_BTN)
   user_btn.begin();
 #endif
@@ -2063,6 +2070,47 @@ bool UITask::dequeueKey(char& c) {
   return true;
 }
 
+// Poll an optional CardKB (I2C keyboard, addr 0x5F) on Wire1/Grove, feeding
+// the same key queue as every physical button. Most of its output needs no
+// translation at all: CardKB's own arrow/Enter/Esc byte codes are already
+// identical to this UI's KEY_LEFT/UP/DOWN/RIGHT/ENTER/CANCEL (0xB4-0xB7, 13,
+// 27), and Backspace (0x08) / printable ASCII (0x20-0x7E) collide with
+// nothing that existed before. Two bytes get remapped:
+//  - Enter, while the on-screen keyboard's plain grid state is active (no
+//    placeholder/accent popup, not in cursor-mode) -- there it means "submit
+//    the field", not KEY_ENTER's usual "commit grid cell (row,col)", which
+//    would otherwise insert a stray character since direct typing never
+//    touches the grid. See KeyboardWidget::handleInput()'s KEY_KB_ENTER
+//    branch.
+//  - Tab (0x09, otherwise unused by any screen) -> KEY_CONTEXT_MENU, the
+//    "Hold-Enter" context-menu gesture used in ~30 places across the UI
+//    (message reply/navigate, Bot/Admin/Repeater menus, ...). CardKB has no
+//    press-duration concept to detect a long-press with, so Tab is the
+//    closest free key standing in for it -- full keyboard-only navigation
+//    would otherwise be unable to reach any of those menus at all.
+void UITask::pollCardKB() {
+#if defined(ENV_PIN_SDA) && defined(ENV_PIN_SCL)
+  if (!_has_cardkb) return;
+  if (millis() - _cardkb_poll_ms < 30) return;   // ~33 Hz poll, plenty for typing
+  _cardkb_poll_ms = millis();
+  Wire1.requestFrom(0x5F, 1);
+  if (!Wire1.available()) return;
+  uint8_t raw = Wire1.read();
+  if (raw == 0) return;   // no key down
+
+  char key;
+  if (raw == 0x0D &&
+      _kb.isVisible() && !_kb._ph_menu.active && !_kb.cursor_mode && !_kb.accent_active) {
+    key = KEY_KB_ENTER;
+  } else if (raw == 0x09) {
+    key = KEY_CONTEXT_MENU;
+  } else {
+    key = (char)raw;
+  }
+  enqueueKey(checkDisplayOn(key));
+#endif
+}
+
 void UITask::loop() {
   // Background delivery: resend pending on-device DMs whose ACK timed out, and
   // finalise the ✗ marker — runs regardless of which screen is active.
@@ -2159,6 +2207,7 @@ void UITask::loop() {
     _analogue_pin_read_millis = millis();
   }
 #endif
+  pollCardKB();
 #if defined(BACKLIGHT_BTN)
   if (millis() > next_backlight_btn_check) {
     bool touch_state = digitalRead(PIN_BUTTON2);

examples/companion_radio/ui-new/UITask.h

@@ -193,6 +193,17 @@ class UITask : public AbstractUITask {
   void enqueueKey(char c);
   bool dequeueKey(char& c);
 
+  // Optional M5Stack CardKB (I2C keyboard, addr 0x5F) on the Grove/Wire1 bus
+  // -- reuses ENV_PIN_SDA/ENV_PIN_SCL (already brought up for
+  // EnvironmentSensorManager) as the "this board has a second I2C bus" gate,
+  // rather than a new board-specific pin define. No-op entirely on boards
+  // without that bus, or when nothing ACKs 0x5F at boot.
+#if defined(ENV_PIN_SDA) && defined(ENV_PIN_SCL)
+  bool     _has_cardkb = false;
+  uint32_t _cardkb_poll_ms = 0;
+#endif
+  void pollCardKB();
+
   void setCurrScreen(UIScreen* c);
 
   // Centred alert overlay (the showAlert() box). Wraps long text to up to

release-notes.md

@@ -6,6 +6,7 @@
 - **Remote Bot gains Actions: `!buzz`, `!gps`, `!advert`.** A new **Actions** toggle (per target — Direct/Channel/Room, nested under each target's existing **Commands** toggle) enables three commands that change the device's own behaviour instead of just reporting on it: `!buzz [seconds]` sounds the buzzer as a find-me signal (default 5s, capped at 30s, sounds even if the buzzer is muted), `!gps on`/`!gps off` toggles GPS, and `!advert` sends an immediate advert. Off by default; combines with the existing query commands in one message the same way (`!batt !gps on` → `4.10V | GPS: on`).
 - **Bot Trigger fields accept multiple phrases.** Pack several trigger words into one Trigger field, comma-separated (`hi,hello there,yo`) — matching any one of them fires the reply, same as before for a single phrase.
 - **Remote Bot Actions gain `!gpio1`..`!gpio4`** (Wio Tracker L1 only — 4 otherwise-unused pins). Each pin is independently set to Off/Input/Output (GPIO1/GPIO2 also offer Analog) from a new **Tools › GPIO** screen; `!gpio1 on`/`!gpio1 off` drives an Output pin remotely, a bare `!gpio1` reports the current mode and reading (including a millivolt value in Analog mode). Gated by the same per-target Actions toggle as `!buzz`/`!gps`/`!advert`.
+- **Optional CardKB support (Wio Tracker L1, Grove I2C) — full keyboard-only navigation.** Plug an M5Stack CardKB into the Grove connector and it's auto-detected at boot — no setting to flip. Typing goes straight into the message/name field instead of navigating the on-screen keyboard grid; arrows, Enter and Esc work as expected everywhere else too (including inside the placeholder and accent popups); Tab opens the Hold-Enter context menu (message reply/navigate, Bot/Admin/Repeater menus, …) — the whole interface is reachable without touching a physical button.
 
 ### Fixes
 

src/helpers/ui/UIScreen.h

@@ -13,6 +13,13 @@
 #define KEY_NEXT           0xF1
 #define KEY_PREV           0xF2
 #define KEY_CONTEXT_MENU   0xF3
+// A literal-ASCII input source's (e.g. an I2C CardKB) Enter, translated only
+// when the on-screen keyboard's plain grid state is active (see
+// UITask::pollCardKB()) -- means "submit the field", not KEY_ENTER's usual
+// "commit whatever grid cell (row,col) is currently selected", which would
+// otherwise insert a stray character since direct typing never touches the
+// grid.
+#define KEY_KB_ENTER       0x05
 
 // "Previous"/"Next" navigation keys: the directional key and its rotary-encoder
 // twin. Decrement / increment a value, or step a selection. (Cancel and the