Add Bluetooth HID remote control support

Integrate BLE keyboard host functionality for page-turner remotes. Adds device pairing, button mapping, preset configurations for Free2/Free3 remotes, and persistent storage of mappings. Migrates from open-x4-sdk to freeink-sdk submodule which includes the BleKeyboardHost library. Implements CPU frequency locking during BLE operations to prevent watchdog timeouts.

platformio.ini

@@ -38,6 +38,16 @@ build_flags =
   -Wno-bidi-chars
   -Wl,--wrap=panic_print_backtrace,--wrap=panic_abort,--wrap=bootloader_common_check_efuse_blk_validity
   -fno-exceptions
+# FreeInk panel profiles: compile both X3 (792x528/UC8253) and X4 (800x480/SSD1677);
+# the firmware picks the active one at runtime via HalDisplay setDisplayX3().
+  -DFREEINK_DEVICE_X3=1
+  -DFREEINK_DEVICE_X4=1
+# BLE HID page-turner host (BleKeyboardHost). NimBLE role/bond config is baked into
+# the prebuilt arduino-esp32 framework's sdkconfig.h, so we don't redefine it here
+# (doing so only warns and has no effect). The host only compiles when
+# FREEINK_CAP_BLE_HID_HOST is set on the env (below); with the capability off,
+# BleKeyboardHost links stubs and pulls in zero NimBLE code.
+  -DFREEINK_BLE_HID_SHOW_UNNAMED_DEVICES=0
 
 build_unflags =
   -std=gnu++11
@@ -57,10 +67,12 @@ extra_scripts =
 
 ; Libraries
 lib_deps =
-  BatteryMonitor=symlink://open-x4-sdk/libs/hardware/BatteryMonitor
-  InputManager=symlink://open-x4-sdk/libs/hardware/InputManager
-  EInkDisplay=symlink://open-x4-sdk/libs/display/EInkDisplay
-  SDCardManager=symlink://open-x4-sdk/libs/hardware/SDCardManager
+  BatteryMonitor=symlink://freeink-sdk/libs/hardware/BatteryMonitor
+  InputManager=symlink://freeink-sdk/libs/hardware/InputManager
+  EInkDisplay=symlink://freeink-sdk/libs/display/FreeInkDisplay
+  SDCardManager=symlink://freeink-sdk/libs/hardware/SDCardManager
+  BleKeyboardHost=symlink://freeink-sdk/libs/network/BleKeyboardHost
+  h2zero/NimBLE-Arduino @ ^2.3.8
   bblanchon/ArduinoJson @ 7.4.2
   ricmoo/QRCode @ 0.0.1
   bitbank2/PNGdec @ 1.1.6
@@ -74,6 +86,7 @@ build_flags =
   ; CROSSPOINT_VERSION is set by scripts/git_branch.py (includes branch + short SHA)
   -DENABLE_SERIAL_LOG
   -DLOG_LEVEL=2 ; Set log level to debug for development builds
+  -DFREEINK_CAP_BLE_HID_HOST=1 ; BLE HID page-turner host (NimBLE)
 
 
 [env:gh_release]
@@ -83,6 +96,7 @@ build_flags =
   -DCROSSPOINT_VERSION=\"${crosspoint.version}\"
   -DENABLE_SERIAL_LOG
   -DLOG_LEVEL=1 ; Set log level to info for release builds
+  -DFREEINK_CAP_BLE_HID_HOST=1 ; BLE HID page-turner host (NimBLE)
 
 [env:gh_release_rc]
 extends = base
@@ -91,6 +105,7 @@ build_flags =
   -DCROSSPOINT_VERSION=\"${crosspoint.version}-rc+${sysenv.CROSSPOINT_RC_HASH}\"
   -DENABLE_SERIAL_LOG
   -DLOG_LEVEL=1 ; Set log level to info for release candidate builds
+  -DFREEINK_CAP_BLE_HID_HOST=1 ; BLE HID page-turner host (NimBLE)
 
 [env:slim]
 extends = base