Phase 0/1: display_setup (LovyanGFX + LVGL) and LVGL theme

- include/theme.h: replace M5Stack-based RGB565 constants with LVGL
  lv_color_hex helpers; same dark-mode palette + tile accent colors,
  portrait SCREEN_W=320 / SCREEN_H=480
- src/display/display_setup.{h,cpp}: custom LGfx device class with
  Panel_ST7796 + Bus_Parallel8 (esp32s3) + Light_PWM + Touch_FT5x06
  (FT6336U is FT5x06 family), setRotation(1) for portrait 320x480
- LVGL display driver with two PSRAM partial draw buffers (320x80)
- LVGL pointer indev wired to LovyanGFX touch readback
- display_loop() drives lv_tick_inc + lv_timer_handler

include/theme.h

@@ -0,0 +1,38 @@
+#pragma once
+#include <lvgl.h>
+
+// Dark-mode theme constants and tile accent colors for the WT32-SC01 Plus
+// dashboard. Replaces the former M5Stack-specific theme.h; the same RGB565
+// values are kept as 16-bit literals so they can be reused both for LVGL
+// (via lv_color_hex) and for direct LovyanGFX drawing if needed.
+namespace Theme {
+
+// Logical portrait resolution after rotation (320 wide x 480 tall).
+constexpr int SCREEN_W = 320;
+constexpr int SCREEN_H = 480;
+
+// Base palette (RGB565 kept for reference; LVGL uses the hex forms below).
+//   BG        0x0000  pure black
+//   BG_CARD   0x1082  very dark grey (tile / separator)
+//   TEXT      0xFFFF  white
+//   TEXT_DIM  0x8410  mid grey
+inline lv_color_t bg()        { return lv_color_hex(0x000000); }
+inline lv_color_t bgCard()    { return lv_color_hex(0x1C1C1E); }
+inline lv_color_t text()      { return lv_color_hex(0xFFFFFF); }
+inline lv_color_t textDim()   { return lv_color_hex(0x9A9A9E); }
+
+// Tile accent backgrounds (muted, iOS-dark-mode style).
+inline lv_color_t accentWeather()  { return lv_color_hex(0x1B3A5C); } // muted blue
+inline lv_color_t accentCalendar() { return lv_color_hex(0x3A2A5C); } // muted purple
+inline lv_color_t accentMvg()      { return lv_color_hex(0x2C5C3A); } // muted green
+
+// Symbol / status colors.
+inline lv_color_t accentSun()      { return lv_color_hex(0xFBC02D); }
+inline lv_color_t accentRain()     { return lv_color_hex(0x4FC3F7); }
+inline lv_color_t accentUBahn()    { return lv_color_hex(0xE62D2D); } // MVV U-Bahn red
+inline lv_color_t accentSBahn()    { return lv_color_hex(0x1A7A3A); } // MVV S-Bahn green
+inline lv_color_t accentWarn()     { return lv_color_hex(0xFFB300); }
+inline lv_color_t accentError()    { return lv_color_hex(0xF44336); }
+inline lv_color_t accentStorm()    { return lv_color_hex(0xFFD54F); }
+
+} // namespace Theme