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.

src/MappedInputManager.h

@@ -7,6 +7,9 @@ class GfxRenderer;
 class MappedInputManager {
  public:
   enum class Button { Back, Confirm, Left, Right, Up, Down, Power, PageBack, PageForward, NavNext, NavPrevious };
+  // Number of values in Button (Back..NavPrevious). Used to size the BLE overlay and
+  // to clamp persisted BLE mappings. Keep in sync with the enum above.
+  static constexpr uint8_t kButtonCount = 11;
 
   struct Labels {
     const char* btn1;
@@ -28,6 +31,23 @@ class MappedInputManager {
   // Returns the raw front button index that was pressed this frame (or -1 if none).
   int getPressedFrontButton() const;
 
+  // --- BLE page-turner overlay -------------------------------------------------
+  // Drain decoded key events from the FreeInk BLE HID host and translate the ones
+  // bound in SETTINGS.bleKeyMap into per-frame logical-button edges that OR into
+  // wasPressed()/isPressed()/wasReleased(). Call once per main-loop iteration,
+  // right after gpio.update() and BleHid.poll(). No-ops when BLE is compiled out.
+  void pollBle();
+  // True when a mapped BLE key produced an edge this frame — keeps the inactivity
+  // / auto-sleep timer alive while a remote is the only input device in use.
+  bool bleHadActivityThisFrame() const { return bleActivityThisFrame; }
+  // Capture mode: while on, pollBle() stops mapping events and instead stashes the
+  // raw decoded key identity so the button-mapping UI can read it without racing the
+  // live mapping over the single popKey() queue.
+  void setBleCaptureMode(bool on);
+  // Pop a captured (kind, value) key identity grabbed while in capture mode.
+  // Returns false when nothing has been captured since the last call.
+  bool takeCapturedBleKey(uint8_t& kind, uint8_t& value);
+
   // True when the control axis is flipped relative to the physical buttons: the user opted into
   // orientation-following front buttons AND the screen is *currently rendered* rotated (INVERTED /
   // LANDSCAPE_CCW). Keyed on the live renderer orientation rather than the persisted reader setting,
@@ -44,4 +64,17 @@ class MappedInputManager {
   const GfxRenderer& renderer;
 
   bool mapButton(Button button, bool (HalGPIO::*fn)(uint8_t) const) const;
+  // OR-in the BLE overlay for a logical button, mirroring mapButton()'s composite
+  // handling of NavNext/NavPrevious so a remote key bound to Up/Down/Left/Right also
+  // drives list navigation.
+  bool bleEdge(const bool* arr, Button button) const;
+
+  // Per-frame BLE overlay, indexed by (uint8_t)Button.
+  bool blePressEdge[kButtonCount] = {};    // press edge this frame   -> wasPressed / isPressed
+  bool bleReleaseEdge[kButtonCount] = {};  // release edge this frame  -> wasReleased
+  bool bleActivityThisFrame = false;
+  bool bleCaptureMode = false;
+  bool bleHasCaptured = false;
+  uint8_t bleCapturedKind = 0xFF;
+  uint8_t bleCapturedValue = 0;
 };