Add experimental support for LilyGo T-Deck Pro E-Paper

Add new board configuration for the LilyGo T-Deck Pro with E-Paper display
(GDEQ031T10, 3.1" 320x240 touchscreen) and 4G LTE modem (A7682E).

Hardware features:
- ESP32-S3FN16R8 (16MB Flash, 8MB PSRAM)
- 3.1" E-Paper display with CST328 capacitive touch
- TCA8418 QWERTY keyboard controller
- SX1262 LoRa radio
- MIA-M10Q GPS module
- A7682E 4G LTE modem (optional)
- 1400mAh battery with BQ25896/BQ27220 management

Known limitations:
- E-Paper display has slow refresh rate (1-2s)
- Temporary ST7789 driver config (needs GxEPD2 integration)
- TCA8418 keyboard driver needs full implementation
- Battery management requires BQ driver implementation

This is an experimental configuration. Full E-Paper support requires
integrating the GxEPD2 library and optimizing the UI for slow refresh rates.

See boards/lilygo-t-deck-pro-epaper/README.md for details.

Author: claude

boards/_boards_json/lilygo-t-deck-pro-epaper.json

@@ -0,0 +1,56 @@
+{
+  "build": {
+    "arduino": {
+      "ldscript": "esp32s3_out.ld",
+      "partitions": "default_16MB.csv",
+      "memory_type": "qio_opi"
+    },
+    "core": "esp32",
+    "extra_flags": [
+      "-DT_DECK_PRO_EPAPER",
+      "-DBOARD_HAS_PSRAM",
+      "-DARDUINO_USB_MODE=1",
+      "-DARDUINO_RUNNING_CORE=1",
+      "-DARDUINO_EVENT_RUNNING_CORE=1",
+      "-DARDUINO_USB_CDC_ON_BOOT"
+    ],
+    "f_cpu": "240000000L",
+    "f_flash": "80000000L",
+    "flash_mode": "qio",
+    "hwids": [
+      [
+        "0x303A",
+        "0x1001"
+      ]
+    ],
+    "mcu": "esp32s3",
+    "variant": "lilygo-t-deck-pro-epaper"
+  },
+  "connectivity": [
+    "wifi",
+    "bluetooth",
+    "lora",
+    "cellular"
+  ],
+  "debug": {
+    "default_tool": "esp-builtin",
+    "onboard_tools": [
+      "esp-builtin"
+    ],
+    "openocd_target": "esp32s3.cfg"
+  },
+  "frameworks": [
+    "arduino",
+    "espidf"
+  ],
+  "name": "LilyGo T-Deck Pro E-Paper (16M Flash 8M PSRAM)",
+  "upload": {
+    "flash_size": "16MB",
+    "maximum_ram_size": 327680,
+    "maximum_size": 16777216,
+    "require_upload_port": true,
+    "speed": 921600
+  },
+  "url": "https://www.lilygo.cc",
+  "vendor": "LilyGo"
+}

boards/lilygo-t-deck-pro-epaper/README.md

@@ -0,0 +1,174 @@
+# LilyGo T-Deck Pro E-Paper - Bruce Firmware
+
+⚠️ **EXPERIMENTAL SUPPORT** ⚠️
+
+This board configuration is experimental and has significant limitations due to the E-Paper display.
+
+## Hardware Specifications
+
+- **MCU**: ESP32-S3FN16R8 (16MB Flash, 8MB PSRAM)
+- **Display**: GDEQ031T10 (3.1" E-Paper, 320x240, UC8253 controller)
+- **Touch**: CST328 capacitive touch controller (I2C 0x1A)
+- **Keyboard**: TCA8418 QWERTY keyboard controller (I2C 0x34)
+- **LoRa**: SX1262 (915/868 MHz)
+- **GPS**: MIA-M10Q (UART)
+- **4G Modem**: A7682E LTE Cat 1 (optional)
+- **Battery**: 1400mAh LiPo with BQ25896 charger and BQ27220 fuel gauge
+- **Gyroscope**: BHI260AP (I2C 0x28)
+- **SD Card**: MicroSD slot (SPI)
+
+## Pin Configuration
+
+### Display (E-Paper)
+- **MOSI**: GPIO 33
+- **SCK**: GPIO 36
+- **CS**: GPIO 34
+- **DC**: GPIO 35
+- **BUSY**: GPIO 37
+- **RST**: Not connected (-1)
+
+### Touch (CST328)
+- **SDA**: GPIO 13
+- **SCL**: GPIO 14
+- **INT**: GPIO 12
+- **RST**: GPIO 45
+
+### Keyboard (TCA8418)
+- **SDA**: GPIO 13
+- **SCL**: GPIO 14
+- **INT**: GPIO 15
+- **LED**: GPIO 42
+
+### LoRa (SX1262)
+- **MOSI**: GPIO 33
+- **MISO**: Not used
+- **SCK**: GPIO 36
+- **CS**: GPIO 3
+- **RST**: GPIO 4
+- **DIO1**: GPIO 5
+- **BUSY**: GPIO 6
+
+### SD Card
+- **MOSI**: GPIO 33
+- **SCK**: GPIO 36
+- **CS**: GPIO 48
+
+### GPS (MIA-M10Q)
+- **TX**: GPIO 16
+- **RX**: GPIO 17
+- **Baud Rate**: 9600
+
+### Power
+- **Power Control**: GPIO 10
+- **Battery ADC**: GPIO 4
+
+## Known Limitations
+
+### E-Paper Display Limitations
+
+1. **Slow Refresh Rate**: E-Paper displays take 1-2 seconds to fully refresh
+   - Bruce's UI expects fast TFT refresh rates
+   - Menus and animations will be very slow and choppy
+   - Not suitable for real-time operations
+
+2. **Ghosting**: E-Paper displays show ghosting effects
+   - Previous images may remain faintly visible
+   - Full screen refreshes needed periodically
+
+3. **Monochrome Only**: E-Paper is black and white
+   - No color support (Bruce UI uses colors extensively)
+   - Reduced visual feedback
+
+4. **No Backlight**: E-Paper has no backlight
+   - Needs external light to be readable
+   - Brightness controls do nothing
+
+### Current Implementation Status
+
+✅ **Working:**
+- Touch input (CST328)
+- Basic GPIO setup
+- Power management
+- SD Card support
+- LoRa module support
+
+⚠️ **Partially Working:**
+- Display output (using TFT_eSPI with ST7789 driver as placeholder)
+  - **CRITICAL**: E-Paper requires GxEPD2 library, not TFT_eSPI
+  - Current config will NOT work correctly with E-Paper
+  - This is a temporary workaround for compilation
+
+❌ **Not Implemented:**
+- Keyboard input (TCA8418 needs proper driver library)
+- 4G Modem (A7682E not supported in Bruce)
+- Gyroscope (BHI260AP not used in Bruce)
+- Battery fuel gauge (BQ27220 reading)
+- Charger status (BQ25896 reading)
+
+## Required Changes for Full E-Paper Support
+
+To properly support the E-Paper display, the following major changes are needed:
+
+1. **Replace TFT_eSPI with GxEPD2**
+   - Add `zinggjm/GxEPD2` library dependency
+   - Create wrapper layer to adapt GxEPD2 API to Bruce's display API
+   - Implement partial refresh strategies to improve performance
+
+2. **Optimize UI for E-Paper**
+   - Reduce refresh frequency
+   - Simplify animations
+   - Use partial refreshes where possible
+   - Convert color schemes to high-contrast B&W
+
+3. **Add TCA8418 Keyboard Driver**
+   - Implement full TCA8418 driver or add library dependency
+   - Map keyboard matrix to ASCII codes
+   - Handle function keys and modifiers
+
+4. **Add Battery Management**
+   - Implement BQ27220 fuel gauge reading
+   - Implement BQ25896 charger status
+   - Proper battery percentage calculation
+
+## Building
+
+```bash
+pio run -e lilygo-t-deck-pro-epaper
+```
+
+## Flashing
+
+```bash
+pio run -e lilygo-t-deck-pro-epaper -t upload
+```
+
+## Recommendations
+
+**For Production Use:**
+- Consider using the regular T-Deck or T-Deck Plus with TFT display
+- Bruce is optimized for fast TFT displays, not E-Paper
+- E-Paper support would require significant UI redesign
+
+**For Testing:**
+- This configuration can be used to test non-display features
+- Keyboard, LoRa, GPS, and other peripherals should work
+- Display will be slow but functional for basic menu navigation
+
+## References
+
+- [LilyGo T-Deck Pro GitHub](https://github.com/Xinyuan-LilyGO/T-Deck-Pro)
+- [LilyGo T-Deck Pro Wiki](https://wiki.lilygo.cc/get_started/en/Wearable/T-Deck-Pro/T-Deck-Pro.html)
+- [GxEPD2 Library](https://github.com/ZinggJM/GxEPD2)
+- [Bruce Firmware](https://github.com/pr3y/Bruce)
+
+## Contributing
+
+If you want to improve E-Paper support:
+1. Implement GxEPD2 wrapper layer
+2. Add TCA8418 keyboard library
+3. Optimize UI for E-Paper refresh rates
+4. Test and submit pull request
+
+---
+
+**Note**: This is an experimental configuration. Use at your own risk.