feat(examples): Update BSP examples which have a display to use a gui class for clearer / more useful example code to start from

[finger563]

Description

Refactors all 13 BSP display examples (esp-box, t-deck, wrover-kit,
matouch-rotary-display, seeed-studio-round-display, byte90,
ws-s3-lcd-1-47, ws-s3-touch, ws-s3-geek, smartpanlee-sc01-plus,
t-dongle-s3, m5stack-tab5, esp32-p4-function-ev-board) so that all LVGL
UI code lives in a per-example Gui class (example/main/gui.hpp +
gui.cpp) instead of ad-hoc statics and lambdas in app_main.

Each Gui class follows the same canonical pattern (modeled on the Gui /
Menu components in esp-box-emu,
without the squareline-generated code):

• Owns a std::recursive_mutex guarding every LVGL call and an espp::Task
  which pumps lv_task_handler() every 16 ms.
• init_ui() is broken into small member functions, one per logical piece of
  the UI (init_background(), init_label(), init_buttons(),
  init_circle_layer(), ...).
• All LVGL events are registered with this as user-data and dispatched
  through a single static trampoline (event_callback) into member handlers.
• The rest of the application interacts with the UI only through small,
  thread-safe, doxygen-documented methods (set_label_text(),
  draw_circle(), clear_circles(), next_rotation(), plus board-specific
  ones such as set_kalman_down() / set_madgwick_down(),
  set_clock_text(), set_status_text(), cycle_brightness()).

The app_mains now contain only board/peripheral init and calls into the
Gui (−2,999 / +410 lines across the 14 modified example mains). The doxygen
//! [<name> example] snippet markers are unchanged, so the rendered docs now
show the much cleaner app_main usage.

Behavior is preserved everywhere (touch-to-draw circles, rotation, keyboard /
encoder / hardware-button handling, IMU gravity lines, RTC clock, LED
animation tasks, audio clicks, networking/RTPS status on the P4 board), with
a few improvements:

• All touch-capable boards gained an on-screen LV_SYMBOL_TRASH clear button
  next to the existing rotate button, exercising multi-button event dispatch
  through the trampoline.
• m5stack-tab5: fixed the hardware brightness button passing 0.25–1.0 to the
  percent-based (0–100) brightness() API — which effectively blanked the
  screen — and added an on-screen brightness button; both now cycle
  25/50/75/100% through a shared Gui::cycle_brightness().
• m5stack-tab5 BSP: fixed a compile failure under
  -Werror=missing-field-initializers (missing .write_then_read designated
  initializer in src/touchpad.cpp).

Motivation and Context

The display examples had grown into large app_main functions full of static
globals, free functions, and lambdas sharing a hand-rolled LVGL mutex — nearly
identical boilerplate duplicated 13 times, and not a good template for users
to build real UIs from. Encapsulating the UI in a Gui class gives users a
copyable, idiomatic starting point for structuring C++ LVGL applications on
top of the espp BSPs (thread-safety, event dispatch, and update-task ownership
all handled in one place), and makes the examples themselves shorter and
easier to follow.

How has this been tested?

• All 13 examples were clean-built (rm -rf build && idf.py build) with
  ESP-IDF v6.0.1 across their respective targets (esp32, esp32s3, esp32p4);
  13/13 pass.
• Verified no raw lv_* calls remain in any example app_main.
• Verified every BSP initialize_* call from the original examples is
  preserved in the refactored ones.
• Verified the doxygen snippet markers are intact in all 13 examples so the
  documentation still renders the example code.
• All new/modified files formatted with the repo's .clang-format.
• Runtime behavior (touch, buttons, rotation, IMU lines, audio) not yet
  re-verified on hardware.

Screenshots (if appropriate, e.g. schematic, board, console logs, lab pictures):

N/A — no visual changes beyond the added clear/brightness buttons.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation Update
• Hardware (schematic, board, system design) change
• Software change

Checklist:

• My change requires a change to the documentation.
• I have added / updated the documentation related to this change via either README or WIKI

Software

• I have added tests to cover my changes.
• I have updated the .github/workflows/build.yml file to add my new test to the automated cloud build github action.
• All new and existing tests passed.
• My code follows the code style of this project.

[github-actions]

✅Static analysis result - no issues found! ✅

[Copilot]

Pull request overview

This PR refactors multiple ESPP BSP display examples to move LVGL UI creation, event dispatch, and LVGL task ownership into per-example Gui classes (example/main/gui.hpp + gui.cpp), leaving app_main focused on board/peripheral initialization and high-level UI interactions.

Changes:

• Introduces per-example Gui classes that encapsulate LVGL objects, a guarded lv_task_handler() pump task, and centralized LVGL event trampolines.
• Updates example app_main implementations to call into the Gui API instead of managing ad-hoc statics/lambdas and LVGL locking.
• Fixes a BSP build warning/error for m5stack-tab5 by adding the missing designated initializer field.

Reviewed changes

Copilot reviewed 40 out of 40 changed files in this pull request and generated 11 comments.

Show a summary per file

File	Description
components/ws-s3-touch/example/main/gui.hpp	New Gui API for ws-s3-touch (labels, buttons, gravity lines, circle layer).
components/ws-s3-touch/example/main/gui.cpp	Implements ws-s3-touch GUI setup, LVGL task loop, event dispatch, circle drawing.
components/ws-s3-lcd-1-47/example/main/ws_s3_lcd_1_47_example.cpp	Refactors example main to use Gui instead of static LVGL helpers.
components/ws-s3-lcd-1-47/example/main/gui.hpp	New Gui API for ws-s3-lcd-1-47 (label + circle layer + rotation).
components/ws-s3-lcd-1-47/example/main/gui.cpp	Implements ws-s3-lcd-1-47 GUI and LVGL update task.
components/ws-s3-geek/example/main/ws_s3_geek_example.cpp	Refactors ws-s3-geek example main to use Gui.
components/ws-s3-geek/example/main/gui.hpp	New Gui API for ws-s3-geek.
components/ws-s3-geek/example/main/gui.cpp	Implements ws-s3-geek GUI and LVGL update task.
components/wrover-kit/example/main/wrover_kit_example.cpp	Refactors wrover-kit example main to use Gui.
components/wrover-kit/example/main/gui.hpp	New Gui API for wrover-kit.
components/wrover-kit/example/main/gui.cpp	Implements wrover-kit GUI and LVGL update task.
components/t-dongle-s3/example/main/t_dongle_s3_example.cpp	Refactors t-dongle-s3 example main to use Gui.
components/t-dongle-s3/example/main/gui.hpp	New Gui API for t-dongle-s3.
components/t-dongle-s3/example/main/gui.cpp	Implements t-dongle-s3 GUI and LVGL update task.
components/t-deck/example/main/gui.hpp	New Gui API for t-deck (buttons + circle layer).
components/t-deck/example/main/gui.cpp	Implements t-deck GUI, event dispatch, and circle drawing.
components/smartpanlee-sc01-plus/example/main/smartpanlee_sc01_plus_example.cpp	Refactors SmartPanlee example main to use Gui and thread-safe UI calls from touch callback.
components/smartpanlee-sc01-plus/example/main/gui.hpp	New Gui API for SmartPanlee (label + buttons + circle layer).
components/smartpanlee-sc01-plus/example/main/gui.cpp	Implements SmartPanlee GUI layout + event dispatch + circle drawing.
components/seeed-studio-round-display/example/main/seeed_studio_round_display_example.cpp	Refactors round-display example main to use Gui.
components/seeed-studio-round-display/example/main/gui.hpp	New Gui API for round-display.
components/seeed-studio-round-display/example/main/gui.cpp	Implements round-display GUI, layout updates, and event dispatch.
components/matouch-rotary-display/example/main/matouch_rotary_display_example.cpp	Refactors matouch rotary display example main to use Gui.
components/matouch-rotary-display/example/main/gui.hpp	New Gui API for matouch rotary display.
components/matouch-rotary-display/example/main/gui.cpp	Implements matouch rotary display GUI, event dispatch, and circle drawing.
components/m5stack-tab5/src/touchpad.cpp	Adds missing designated initializer field (.write_then_read) to satisfy -Wmissing-field-initializers.
components/m5stack-tab5/example/main/gui.hpp	New Gui API for tab5 (gravity lines + brightness cycling + buttons).
components/m5stack-tab5/example/main/gui.cpp	Implements tab5 GUI, gravity line updates, and brightness cycling.
components/esp32-p4-function-ev-board/example/main/gui.hpp	New Gui API for P4 EV board (title + status + buttons + circles).
components/esp32-p4-function-ev-board/example/main/gui.cpp	Implements P4 EV board GUI, event dispatch, and circle drawing.
components/esp32-p4-function-ev-board/example/main/esp32_p4_function_ev_board_example.cpp	Refactors P4 EV board example main to use Gui for status and touch-to-draw.
components/esp-box/example/main/gui.hpp	New Gui API for esp-box (gravity lines + buttons + circles).
components/esp-box/example/main/gui.cpp	Implements esp-box GUI and gravity line vector remapping.
components/byte90/example/main/gui.hpp	New Gui API for byte90 (label + circles + rotation).
components/byte90/example/main/gui.cpp	Implements byte90 GUI and circle drawing.
components/byte90/example/main/byte90_example.cpp	Refactors byte90 example main to use Gui.