Replace USB serial/HID with Bluetooth Low Energy

Move all communication from USB to BLE. The device now advertises as
"Claude Controller" and acts as both a BLE HID keyboard (for touch
gestures) and a GATT data server (for usage updates from the daemon).

- Add NimBLE-Arduino BLE module with custom GATT service + HID keyboard
- Add third screen (Bluetooth) with connection status, MAC, reset button
- Rewrite daemon in bash using bluetoothctl/busctl for BLE GATT writes
- Add screenshot capture via LVGL snapshot over serial
- Remove TinyUSB mode — normal pio upload works again
- Update README with BLE architecture, screenshots, gesture docs

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

flash.sh

@@ -1,7 +1,5 @@
 #!/bin/bash
-# Flash helper for TinyUSB mode firmware.
-# The built-in JTAG bootloader doesn't auto-reset with TinyUSB, so we
-# trigger a reset via DTR/RTS on the CDC serial port before flashing.
+# Build and flash firmware to the SC01 Plus.
 set -e
 
 SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
@@ -11,34 +9,8 @@ echo "=== Flashing Claude Usage Tracker ==="
 echo "Port: $PORT"
 echo ""
 
-# Build first
-echo "[1/3] Building firmware..."
 cd "$SCRIPT_DIR/firmware"
-~/.platformio/penv/bin/pio run
-
-# Reset the device into bootloader via DTR/RTS
-echo "[2/3] Resetting device into bootloader..."
-python3 -c "
-import serial, time
-port = serial.Serial('$PORT', 115200)
-port.dtr = False; port.rts = True; time.sleep(0.1)
-port.dtr = True; port.rts = False; time.sleep(0.05)
-port.dtr = False; time.sleep(0.1); port.close()
-"
-sleep 0.5
-
-# Flash with no_reset (device is already in bootloader)
-echo "[3/3] Flashing..."
-python3 ~/.platformio/packages/tool-esptoolpy/esptool.py \
-    --chip esp32s3 \
-    --port "$PORT" \
-    --before no_reset \
-    --baud 921600 \
-    write_flash -z \
-    0x0 .pio/build/sc01plus/bootloader.bin \
-    0x8000 .pio/build/sc01plus/partitions.bin \
-    0xe000 ~/.platformio/packages/framework-arduinoespressif32/tools/partitions/boot_app0.bin \
-    0x10000 .pio/build/sc01plus/firmware.bin
+~/.platformio/penv/bin/pio run -t upload --upload-port "$PORT"
 
 echo ""
-echo "=== Done! Device will reboot automatically. ==="
+echo "=== Done! ==="