fix(gamepad): truncate stick/trigger axes uniformly across clients (G25)

Apple's GamepadCapture rounded axis values (`(v * scale).rounded()`) while
SDL-core and Android truncate, so a half-pressed control emitted 128 on Apple
vs 127 elsewhere. Drop `.rounded()` so `Int32(Float)` truncates toward zero on
Apple too; rails are unchanged (full deflection stays 255 / ±32767).

Also clamp SDL-core's LeftX/RightX to a symmetric -32767 like the Y axes and
the other clients already do, instead of letting the raw i16 reach -32768.

Verified: Apple `swift build` + full PunktfunkKit suite (124 pass); SDL half
on Windows .173 `cargo clippy -p pf-client-core -- -D warnings` (green).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

clients/apple/Sources/PunktfunkKit/Gamepad/GamepadCapture.swift

@@ -271,12 +271,12 @@ public final class GamepadCapture {
             slot.buttons = newButtons
         }
         let newAxes: [Int32] = [
-            Int32((g.leftThumbstick.xAxis.value * 32767).rounded()),
-            Int32((g.leftThumbstick.yAxis.value * 32767).rounded()),
-            Int32((g.rightThumbstick.xAxis.value * 32767).rounded()),
-            Int32((g.rightThumbstick.yAxis.value * 32767).rounded()),
-            Int32((g.leftTrigger.value * 255).rounded()),
-            Int32((g.rightTrigger.value * 255).rounded()),
+            Int32(g.leftThumbstick.xAxis.value * 32767),
+            Int32(g.leftThumbstick.yAxis.value * 32767),
+            Int32(g.rightThumbstick.xAxis.value * 32767),
+            Int32(g.rightThumbstick.yAxis.value * 32767),
+            Int32(g.leftTrigger.value * 255),
+            Int32(g.rightTrigger.value * 255),
         ]
         for (i, v) in newAxes.enumerated() where v != slot.axes[i] {
             connection.send(.gamepadAxis(UInt32(i), value: v, pad: slot.pad))