Remove dead code (#11082)

Removed:
- MessageStore::addFromPacket and addFromString, superseded by
  tryAddFromPacket
- GeoCoord rangeRadiansToMeters, distanceTo, bearingTo
- Router::rawSend, declared virtual with no override and no caller
- ContentHandler handleHotspot, handleFs, handleAdminSettings,
  handleAdminSettingsApply, handleDeleteFsContent and their commented
  route registrations, plus the now unreachable htmlDeleteDir and the
  handleUpdateFs declaration that had no definition
- ContentHelper replaceAll
- OnScreenKeyboardModule popup chain: showPopup, clearPopup, drawPopup,
  drawPopupOverlay and their state, unreachable since the frame based UI
  was replaced by baseUI
- DebugRenderer drawDebugInfoTrampoline, drawDebugInfoSettingsTrampoline
  and the orphaned drawFrameSettings
- NodeListRenderer calculateMaxScroll, drawColumns and a stale extern
  haveGlyphs declaration with no definition
- UIRenderer::haveGlyphs, Screen::blink,
  NotificationRenderer::showKeyboardMessagePopupWithTitle,
  VirtualKeyboard::getInputText
- InkHUD touchNavLeft, touchNavRight, Applet::getActiveNodeCount,
  ThreadedMessageApplet::saveMessagesToFlash
- TwoButton::setHandlerUp, TwoButtonExtended setHandlerUp,
  setJoystickDownHandlers, setJoystickUpHandlers
- CannedMessageModule LaunchRepeatDestination, isCharInputAllowed,
  hasMessages
- TrafficManagementModule resetStats, recordRouterHopPreserved,
  saturatingIncrement
- UnitConversions::MetersPerSecondToMilesPerHour
- EncryptedStorage getSessionRemainingSeconds
- BMI270Sensor::writeRegisters, GPS::hasFlow, FSCommon copyFile,
  SerialConsole consolePrintf, buzz playLongPressLeadUp,
  memGet displayPercentHeapFree

src/modules/CannedMessageModule.h

@@ -55,7 +55,6 @@ class CannedMessageModule : public SinglePortModule, public Observable<const UIF
     CannedMessageModule();
 
     void LaunchWithDestination(NodeNum, uint8_t newChannel = 0);
-    void LaunchRepeatDestination();
     void LaunchFreetextWithDestination(NodeNum, uint8_t newChannel = 0);
 
     // === Emote Picker navigation ===
@@ -70,11 +69,9 @@ class CannedMessageModule : public SinglePortModule, public Observable<const UIF
 
     // === State/UI ===
     bool shouldDraw();
-    bool hasMessages();
     void resetSearch();
     void updateDestinationSelectionList();
     void drawDestinationSelectionScreen(OLEDDisplay *display, OLEDDisplayUiState *state, int16_t x, int16_t y);
-    bool isCharInputAllowed() const;
     String drawWithCursor(String text, int cursor);
 
     // === Emote Picker ===