Keyboard and Xbox-gamepad input drive the panel

New input pipeline: sources feed an InputRouter (VRio.Core.Input) that
calls the same VRioDevice press/release/axis entry points the mouse
canvas uses, so routed input is indistinguishable on the wire.

- Bindings live in %APPDATA%\vRIO\bindings.txt (plain text, commented
  defaults written on first run; Reload/Edit buttons in the new Input
  group). Keys and pad buttons press any RIO address, momentary or
  toggle; axes bind in normalized units of each axis realistic travel
  window with deflect (spring-back), rate (position holds), deadzone,
  and invert options - RioAxisRange supplies the wire signs.
- Router suppresses key auto-repeat, edge-detects pad buttons, and
  hold-counts per address so overlapping sources press once and
  release last; axes only write when the composed value changes, so
  mouse drags keep working while sources idle.
- Xbox pad via a zero-dependency XInput P/Invoke poller (xinput1_4,
  fallback xinput9_1_0), throttled rescan while disconnected.
- MainForm intercepts bound keys in ProcessCmdKey so arrows/space
  reach the panel instead of moving focus; keys release on focus
  loss; center-axes and host ResetRequest reset the rate integrators.
- Canvas highlights router-held addresses like clicks.
- Defaults: arrows=stick, W/S=throttle, Q/E=pedals, numpad=internal
  keypad, IJKL/Space=hat+main; pad left stick/triggers/right stick =
  stick/pedals/throttle-rate, ABXY/dpad/shoulders = named buttons.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

README.md

@@ -23,6 +23,15 @@ controls:
 - Cells shade to the **lamp state the host commands** (`LampRequest`:
   off / dim / bright, with slow/med/fast flash), so RIOJoy's press-feedback
   lights the on-screen panel just like the real buttons.
+- **Keyboard and Xbox (XInput) controller input** drive the same controls
+  through a bindings file (`%APPDATA%\vRIO\bindings.txt`, created with
+  commented defaults on first run — *Edit bindings…* opens it, *Reload
+  bindings* applies edits live). Keys and pad buttons press any RIO address;
+  pad sticks/triggers and keys drive the axes in each axis' realistic travel
+  window, with deflect (spring-back), rate (throttle-style, position holds),
+  deadzone, and invert options. Defaults: arrows = stick, W/S = throttle,
+  Q/E = pedals, numpad = internal keypad, IJKL/Space = hat + main, left
+  stick / triggers / right stick = stick / pedals / throttle on the pad.
 
 ## Wire behavior