refactor(host/W4): extract inject keymap tables + rehome HidoutDedup

Two device-agnostic pieces carved out of the inject facade (plan §W4):

- inject/keymap.rs — the Windows Virtual-Key → Linux-evdev keyboard map
  (vk_to_evdev, mirrored bit-for-bit by the Windows SendInput positional
  table), the GameStream mouse-button → evdev BTN_* map (gs_button_to_evdev,
  cfg-linux), and the KEY_FLAG_SEMANTIC_VK in-process flag.
- inject/hidout_dedup.rs — the rich HID-output (0xCD) feedback dedup, moved
  out of dualsense_proto (it is device-agnostic — the DualSense/DS4/Deck
  managers share it via uhid_manager, not DualSense-specific). Its unit test
  moves with it.

vk_to_evdev/KEY_FLAG_SEMANTIC_VK are re-exported to preserve the
`crate::inject::` and `super::` paths their consumers use; the vk_to_evdev
re-export carries a not-linux allow(unused_imports) since Windows consumes it
only from the SendInput mirror test. uhid_manager's import repointed to the
new home.

Pure move; no behavior change. Linux clippy+tests + Windows host clippy
(nvenc,amf-qsv) both green; fmt clean.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

crates/punktfunk-host/src/inject/proto/dualsense_proto.rs

@@ -535,124 +535,10 @@ pub fn parse_ds_output(pad: u8, data: &[u8], fb: &mut DsFeedback) {
     }
 }
 
-/// Per-pad dedup for the DualSense HID-output feedback plane (0xCD). A game's DualSense output report
-/// bundles rumble + lightbar + player-LEDs + adaptive-triggers into one report, so a pad that is
-/// merely *rumbling* re-sends its (unchanged) lightbar / LED / trigger state on every output report.
-/// The managers already dedup rumble; this does the same for the rich [`HidOutput`] feedback so the
-/// 0xCD plane carries only genuine changes. State (`Led` / `PlayerLeds` / `Trigger`) is deduped by
-/// value; a one-shot `TrackpadHaptic` pulse is always forwarded (each pulse must fire).
-#[derive(Clone, Default)]
-pub struct HidoutDedup {
-    led: Option<(u8, u8, u8)>,
-    player_leds: Option<u8>,
-    /// Last-forwarded adaptive-trigger effect per side: `[0]` = L2, `[1]` = R2.
-    trigger: [Option<Vec<u8>>; 2],
-}
-
-impl HidoutDedup {
-    /// Forget all remembered state — call when a pad is created or unplugged so the first feedback
-    /// after a (re)connect is always forwarded.
-    pub fn clear(&mut self) {
-        *self = HidoutDedup::default();
-    }
-
-    /// Whether `h` should be forwarded: `true` for a genuine change (remembering the new value) or a
-    /// one-shot pulse; `false` if it repeats the last-forwarded value for its kind.
-    pub fn should_forward(&mut self, h: &HidOutput) -> bool {
-        match h {
-            HidOutput::Led { r, g, b, .. } => {
-                let v = Some((*r, *g, *b));
-                if self.led == v {
-                    false
-                } else {
-                    self.led = v;
-                    true
-                }
-            }
-            HidOutput::PlayerLeds { bits, .. } => {
-                let v = Some(*bits);
-                if self.player_leds == v {
-                    false
-                } else {
-                    self.player_leds = v;
-                    true
-                }
-            }
-            HidOutput::Trigger { which, effect, .. } => {
-                let slot = (*which as usize).min(1);
-                if self.trigger[slot].as_deref() == Some(effect.as_slice()) {
-                    false
-                } else {
-                    self.trigger[slot] = Some(effect.clone());
-                    true
-                }
-            }
-            // One-shot haptic pulse (Steam voice-coil) — state-less, always fires.
-            HidOutput::TrackpadHaptic { .. } => true,
-            // Raw as-is passthrough reports must NEVER dedup: the physical device's firmware
-            // watchdogs RELY on identical periodic refreshes (Triton rumble re-sent every ~40 ms
-            // against a ~50 ms safety timeout, lizard-off every ~3 s) — dropping a repeat would
-            // silence the motors / re-enable lizard mode on the real controller.
-            HidOutput::HidRaw { .. } => true,
-        }
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;
 
-    /// `HidoutDedup` forwards a value once, drops exact repeats, re-forwards a change, tracks the two
-    /// trigger sides independently, never dedups one-shot haptic pulses, and re-arms after `clear`.
-    #[test]
-    fn hidout_dedup_forwards_only_changes() {
-        let mut d = HidoutDedup::default();
-        let led = |r| HidOutput::Led {
-            pad: 0,
-            r,
-            g: 0,
-            b: 0,
-        };
-        // First value forwards; an exact repeat is dropped; a change forwards again.
-        assert!(d.should_forward(&led(10)));
-        assert!(!d.should_forward(&led(10)));
-        assert!(d.should_forward(&led(20)));
-
-        // Player LEDs dedup on their own field, independent of the lightbar.
-        let pl = |bits| HidOutput::PlayerLeds { pad: 0, bits };
-        assert!(d.should_forward(&pl(0b101)));
-        assert!(!d.should_forward(&pl(0b101)));
-        assert!(!d.should_forward(&led(20))); // lightbar still unchanged
-
-        // The two adaptive triggers (L2=0, R2=1) are tracked separately.
-        let trig = |which, byte| HidOutput::Trigger {
-            pad: 0,
-            which,
-            effect: vec![byte, 0, 0],
-        };
-        assert!(d.should_forward(&trig(0, 1)));
-        assert!(d.should_forward(&trig(1, 1))); // same bytes, other side → still forwards
-        assert!(!d.should_forward(&trig(0, 1)));
-        assert!(d.should_forward(&trig(0, 2))); // L2 effect changed
-
-        // One-shot haptic pulses are never deduped.
-        let haptic = HidOutput::TrackpadHaptic {
-            pad: 0,
-            side: 0,
-            amplitude: 1,
-            period: 2,
-            count: 3,
-        };
-        assert!(d.should_forward(&haptic));
-        assert!(d.should_forward(&haptic));
-
-        // `clear` re-arms every kind.
-        d.clear();
-        assert!(d.should_forward(&led(20)));
-        assert!(d.should_forward(&pl(0b101)));
-        assert!(d.should_forward(&trig(0, 2)));
-    }
-
     /// The Steam dual-pad → DualSense touchpad SPLIT: left pad (surface 1) lands contact 0
     /// on the left half, right pad (surface 2) contact 1 on the right half; y follows the
     /// shared screen convention (top → 0) with no flip; pad clicks set the touchpad-click