feat(repeater): dedicated Tools screen + optional radio profile

Move the repeater controls out of Settings > Radio (where the indented sub-item
labels collided with the value column on a 128px OLED) onto their own full-width
Tools > Repeater screen, holding the toggle, the five flood-politeness filters,
and live forwarding stats (Forwarded / Pool free / Queue) together. Toggle text
standardised to ON/OFF throughout.

Adds an optional dedicated radio profile (Network: Current/Custom): enabling the
repeater can switch the radio to a preset/manual freq/bw/sf/cr and disabling
restores the companion's params (revert-on-disable). A profile equal to the
companion = same network; a different one = drop onto a separate repeater
network. MyMesh::applyRepeaterRadio() is the single decision point (boot + every
toggle/edit), gated by repeaterProfileValid(); the profile re-applies after a
reboot left with the repeater on. Persisted behind schema 0xC0DE0010, cleared to
off when an upgraded file yields an invalid config.

Docs updated (settings_screen, tools_screen, README, FEATURES).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

examples/companion_radio/ui-new/UITask.cpp

@@ -126,6 +126,7 @@ static const int QUICK_MSGS_MAX = 10;
 #include "TrailScreen.h"
 #include "CompassScreen.h"
 #include "DiagnosticsScreen.h"
+#include "RepeaterScreen.h"
 #include "ToolsScreen.h"
 
 #ifndef BATT_MIN_MILLIVOLTS
@@ -1200,6 +1201,7 @@ void UITask::begin(DisplayDriver* display, SensorManager* sensors, NodePrefs* no
   trail_screen       = new TrailScreen(this, &_trail);
   compass_screen     = new CompassScreen(this);
   diag_screen        = new DiagnosticsScreen(this);
+  repeater_screen    = new RepeaterScreen(this);
   applyBrightness();
   applyFont();
   applyRotation();
@@ -1250,6 +1252,11 @@ void UITask::gotoDiagnosticsScreen() {
   setCurrScreen(diag_screen);
 }
 
+void UITask::gotoRepeaterScreen() {
+  ((RepeaterScreen*)repeater_screen)->enter();
+  setCurrScreen(repeater_screen);
+}
+
 void UITask::gotoAutoAdvertScreen() {
   ((AutoAdvertScreen*)auto_advert_screen)->enter();
   setCurrScreen(auto_advert_screen);