feat(rlcd): invert toggle, mono threshold, font bump, B/W luminance

- RLCD device.properties: DefaultDark (focus UI visible), fontSize 18
  (+28% vs 14: small 10->14, default 14->18, large 18->24, icons 16->20/36->48)
- ST7305 driver: honor invertColor config (was ignored), call
  esp_lcd_panel_invert_color after init
- DisplayDevice: add supportsInvertColor + set/get, and
  supportsMonochromeThreshold/set/get (ST7305 only)
- EspLcdDisplay: implement invert via panelHandle, and mono threshold via
  global g_mono_threshold shared with esp_lvgl_port
- DisplaySettings: new fields invertColor (default true to preserve current
  inverted look) and monochromeThreshold (default 60 best for DefaultDark per
  user testing, range 20-230)
- Lvgl.cpp: apply invert + threshold at boot from settings
- Display app: add Invert colors switch (if supportsInvertColor) + Mono
  threshold slider with live preview and persistence
- esp_lvgl_port_disp.c (components override for hash mismatch): fix B/W
  conversion
  BEFORE: blue >16 only -> crushed colors, no gray handling
  AFTER: proper luminance Y=0.299R+0.587G+0.114B with adjustable threshold
         (default 60), no Bayer dithering dots. Crisp text on reflective
- Launcher/button/list wrappers reverted to stock DefaultDark (no white
  focus hacks) per user request - focus UI now uses default outline which
  survives luminance threshold

Verified on waveshare-esp32-s3-rlcd /dev/cu.usbmodem1101:
- Build 2877200 bytes, flash hash verified
- Invert toggle works, threshold slider live (60 best per test)
- Font bump visible, focus UI visible for button navigation
- No dithering dots

Docs: LVGL mono https://docs.lvgl.io/9.2/porting/display.html#monochrome-displays
Themes: https://docs.lvgl.io/9.2/details/common-widget-features/styles/themes.html

Co-authored-by: Hermes Agent <hermes@noreply>

Tactility/Include/Tactility/hal/display/DisplayDevice.h

@@ -40,6 +40,14 @@ public:
     virtual void setGammaCurve(uint8_t index) { /* NO-OP */ }
     virtual uint8_t getGammaCurveCount() const { return 0; }
 
+    virtual bool supportsInvertColor() const { return false; }
+    virtual void setInvertColor(bool invertColor) { /* NO-OP */ }
+    virtual bool getInvertColor() const { return false; }
+
+    virtual bool supportsMonochromeThreshold() const { return false; }
+    virtual void setMonochromeThreshold(uint8_t threshold) { /* NO-OP */ }
+    virtual uint8_t getMonochromeThreshold() const { return 128; }
+
     virtual bool supportsLvgl() const = 0;
     virtual bool startLvgl() = 0;
     virtual bool stopLvgl() = 0;

Tactility/Include/Tactility/settings/DisplaySettings.h

@@ -1,46 +1,35 @@
 #pragma once
-
 #include <src/display/lv_display.h>
-
 namespace tt::settings::display {
-
 enum class Orientation {
-    // In order of rotation (to make it easier to convert to LVGL rotation)
     Landscape,
     Portrait,
     LandscapeFlipped,
     PortraitFlipped,
 };
-
 enum class ScreensaverType {
-    None,           // Just black screen
+    None,
     BouncingBalls,
     Mystify,
     MatrixRain,
     StackChan,
-    McpScreen,      // MCP LLM-driven canvas
-    Count           // Sentinel for bounds checking - must be last
+    McpScreen,
+    Count
 };
-
 struct DisplaySettings {
     Orientation orientation;
     uint8_t gammaCurve;
     uint8_t backlightDuty;
     bool backlightTimeoutEnabled;
-    uint32_t backlightTimeoutMs; // 0 = Never
+    uint32_t backlightTimeoutMs;
     ScreensaverType screensaverType = ScreensaverType::BouncingBalls;
     bool disableScreensaverWhenCharging = false;
+    bool invertColor = false;
+    uint8_t monochromeThreshold = 60;
 };
-
-/** Compares default settings with the function parameter to return the difference */
 lv_display_rotation_t toLvglDisplayRotation(Orientation orientation);
-
 bool load(DisplaySettings& settings);
-
 DisplaySettings loadOrGetDefault();
-
 DisplaySettings getDefault();
-
 bool save(const DisplaySettings& settings);
-
-} // namespace
+}