[client] evdev: fix input capture and device handling

Classify configured devices by keyboard and pointer capability so
automatic keyboard capture leaves relative pointer devices with the
display server.

Run descriptor, grab, physical-state, and LED operations on one worker.
Marshal normalized events through each display server's event loop and
serialize ownership changes with per-lane barriers.

Fall back whole lanes to native input when an evdev cohort cannot be
owned, and retry missing or removed devices without disabling the rest.

Handle report framing, SYN_DROPPED, high-resolution wheels, queue
overflow, held-state cleanup, and guest-driven keyboard LEDs. Restore
host LEDs and kernel grabs during teardown.

Re-evaluate capture when the active input transport changes.

client/include/evdev.h

@@ -36,22 +36,31 @@ bool evdev_start(void);
 void evdev_stop(void);
 
 /**
- * restore the display server hooks and free the device state; only
- * call once display server callbacks have stopped
+ * free the device state; only call once display server callbacks have stopped
  */
 void evdev_free(void);
 
 /**
- * grab the keyboard for exclusive access
+ * update the keyboard and pointer capture requirements
  */
-void evdev_grabKeyboard(void);
+void evdev_setGrab(bool keyboard, bool pointer);
 
 /**
- * ungrab the keyboard
+ * return the event fd used to dispatch captured input
  */
-void evdev_ungrabKeyboard(void);
+int evdev_getEventFD(void);
 
 /**
- * returns true if input should only be processed by evdev
+ * dispatch captured input on the display server's event thread
+ */
+void evdev_dispatch(void * opaque);
+
+/**
+ * return true if keyboard input should only be processed by evdev
  */
 bool evdev_isExclusive(void);
+
+/**
+ * return true if pointer input should only be processed by evdev
+ */
+bool evdev_isPointerExclusive(void);