feat(boards): Add Seeed SenseCap Indicator D1L support

[carroarmato0]

Summary

This PR adds firmware support for the Seeed Studio SenseCap Indicator D1L, following the HAL abstraction introduced in PR #25. It supersedes the earlier PR #13 which used #ifdef TARGET_SENSECAP throughout shared code.

Hardware

Component	Details
SoC	ESP32-S3, OPI PSRAM, 8 MB flash
Display	480×480 ST7701S, RGB parallel interface
Touch	FT6x36 at I2C 0x48 (non-standard address), panel mounted 180°
IO expander	PCA9535 at I2C 0x20 — gates LCD SPI CS (P04) and touch RST (P07)
Button	GPIO 38, active-LOW, drives screen cycle / wake via power_hal_pwr_pressed
Battery / PMU	None
IMU	None

New files

All board-specific code lives in firmware/src/boards/sensecap_indicator_d1l/:

• board.h — pin definitions, I2C addresses, BOARD_HAS_* flags
• io_expander.h / io_expander.cpp — minimal PCA9535 raw-I2C driver (port 0 only, no external library)
• board_init.cpp — Wire.begin + io_expander_init (must run before display_hal_init)
• caps.cpp — BoardCaps instance
• display.cpp — Arduino_RGB_Display driver; ST7701S init sequence over SPI gated by PCA9535 CS; PWM backlight on GPIO 45
• touch.cpp — vendored minimal FT6x36 reader; 50 Hz poll (no INT pin); both axes flipped for 180° mount
• power.cpp — edge-detected GPIO 38 PWR button at 50 Hz; all battery stubs return -1/false
• input.cpp — stubs returning false (device has no microphone; PTT not applicable)
• imu.cpp — no-op stubs

Shared-code changes (firmware/src/ui.cpp)

Two board-agnostic fixes proposed for upstream:

1. Battery icon respects board_caps().has_battery — apply_battery_visibility() was documented to hide the battery widget on boards without a battery, but the check was never implemented. Fixed.

2. Swipe gesture navigation — left/right swipes cycle screens; tap still toggles splash. Works on all boards. Also fixes a LVGL 9 quirk where a swipe fires a spurious LV_EVENT_CLICKED at lift-off (400 ms debounce guard in global_click_cb). make_panel() now explicitly sets LV_OBJ_FLAG_GESTURE_BUBBLE alongside EVENT_BUBBLE.

Hardware notes

• ST7701S colour register: 0xCD = 0x08 (not 0x00 as in the Arduino_GFX type9 default — wrong value produces a permanent green tint).
• No INPUT_BTN_PRIMARY: the D1L has no BOOT/GPIO0 button available as a general input. GPIO 38 is repurposed as the PWR button via power_hal_pwr_pressed; voice-mode PTT is permanently false, which is correct since the device has no microphone.
• power_hal_is_vbus_in() returns false: the device has no USB VBUS detection. This intentionally allows the idle system to sleep the display after the timeout — desirable for a desk device that may run 24/7.
• RGB parallel (non-QSPI) display: the porting guide mentions QSPI AMOLED panels, but the HAL contract is interface-only and accommodates the RGB parallel driver without any HAL changes.

Test plan

• All three envs compile (sensecap_indicator_d1l, waveshare_amoled_216, waveshare_amoled_18)
• Flashed and booted on hardware — splash animation visible, PCA9535 init OK, FT6x36 touch init OK
• Button (GPIO 38) cycles screens and wakes from sleep
• Touch swipe navigates screens; tap toggles splash
• Battery icon hidden (no battery on this board)
• No regressions on existing board envs

[carroarmato0]