Initial commit: ESP32-C3 WiFi→BLE bridge for Phomemo M110

- BLE client (NimBLE) with auto-scan/reconnect
- ESC/POS protocol encoder (GS v 0 raster)
- Web API: /api/status, /api/connect, /api/print
- Web UI: image upload with dithering, QR codes, positioning
- Client-side QR generation (qrcode-generator)
- Supports bitmap, QR, and raw ESC/POS print types

platformio.ini

@@ -0,0 +1,20 @@
+[env:esp32c3]
+platform = espressif32
+board = esp32-c3-devkitm-1
+framework = arduino
+monitor_speed = 115200
+upload_speed = 460800
+board_build.mcu = esp32c3
+board_build.variant = esp32c3
+board_build.filesystem = littlefs
+build_unflags = -std=gnu++11
+build_flags = -std=gnu++17 -DARDUINO_USB_MODE=1 -DARDUINO_USB_CDC_ON_BOOT=1
+    -DWIFI_SSID='"FRITZ!Box 7312"'
+    -DWIFI_PASS='"88767327694885648772"'
+    -DPRINTER_BLE_NAME='"Q199G4180950002"'
+
+lib_deps =
+    h2zero/NimBLE-Arduino@^2.5.0
+    esphome/ESPAsyncWebServer-esphome@^3.3.2
+    bblanchon/ArduinoJson@^7.3.0
+    ricmoo/QRCode@^0.0.1