feat(gamepad/apple): send Share/Create as BTN_MISC1 + pin wire bits to the C ABI

G5: buttonMask mapped the dedicated share/create/capture element onto BTN_BACK,
the same bit as View (buttonOptions). On an Xbox-Series pad those are two
distinct physical buttons, so Share was indistinguishable from View on the
host and never delivered the capture bit the host already decodes (DualSense
mute / Steam quick-access). Route it to BTN_MISC1 instead, matching the Rust
client's `Button::Misc1 => wire::BTN_MISC1`. Adds `misc1` to GamepadWire and
allButtons so a held capture button is released on flush like the others.
(On-glass verify owed on a real Xbox-Series pad; a clone pad that exposes one
button as both buttonOptions and Share now emits back+misc1 for it — harmless
on a plain xpad session and rare otherwise.)

G22 (partial): define paddle1..4 for wire completeness, but leave them out of
buttonMask/allButtons until the GameController paddleButton1..4 ↔ BTN_PADDLE
physical correspondence is confirmed on a real Elite pad.

G15: replace the 3-bit spot-check with an exhaustive assertion of every
GamepadWire button/axis constant against the generated C ABI header
(punktfunk_core.h), so any Swift-side drift from punktfunk_core::input::gamepad
fails CI.

swift build + full PunktfunkKit suite green (124 passed, 5 skipped).

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

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

@@ -305,11 +305,15 @@ public final class GamepadCapture {
         if g.dpad.right.isPressed { b |= GamepadWire.dpadRight }
         if g.buttonMenu.isPressed { b |= GamepadWire.start }
         if g.buttonOptions?.isPressed == true { b |= GamepadWire.back }
-        // The share/create/capture element (Xbox Series share, a clone pad's screenshot button —
+        // The dedicated share/create/capture element (Xbox-Series Share, DualSense Create, a clone
-        // e.g. the GameSir G8's, below its d-pad) folds into back/select too. On pads that expose
+        // pad's screenshot button — e.g. the GameSir G8's, below its d-pad) → the wire's capture
-        // the create button BOTH as buttonOptions and as the share element this OR is harmless —
+        // bit, matching the Rust client's `Button::Misc1 => wire::BTN_MISC1`. On an Xbox-Series pad
-        // same wire bit.
+        // this is a button physically DISTINCT from View (buttonOptions, above), so it must not
-        if g.buttons[GCInputButtonShare]?.isPressed == true { b |= GamepadWire.back }
+        // collapse onto back — the host reads MISC1 as its own control (DualSense mute / Steam
+        // quick-access). Caveat: a pad that surfaces ONE physical button as both buttonOptions and
+        // this share element now emits back+misc1 for it — harmless on a plain xpad session (no
+        // misc button) and rare otherwise. NOTE: on-glass verify on a real Xbox-Series pad.
+        if g.buttons[GCInputButtonShare]?.isPressed == true { b |= GamepadWire.misc1 }
         if g.leftThumbstickButton?.isPressed == true { b |= GamepadWire.leftStickClick }
         if g.rightThumbstickButton?.isPressed == true { b |= GamepadWire.rightStickClick }
         if g.leftShoulder.isPressed { b |= GamepadWire.leftShoulder }

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

@@ -26,11 +26,27 @@ public enum GamepadWire {
     public static let y: UInt32 = 0x8000
     /// DualSense touchpad click (Moonlight's extended-button bit position).
     public static let touchpadClick: UInt32 = 0x10_0000
+    /// Misc / capture button — Xbox-Series Share, DualSense Create, Steam-Deck quick-access
+    /// (Moonlight's extended-button namespace; `input::gamepad::BTN_MISC1`). The host routes it to
+    /// the DualSense mute / Steam quick-access menu; a plain virtual xpad has no such button.
+    public static let misc1: UInt32 = 0x0020_0000
+    /// Back-grip paddles (Xbox Elite P1–P4 / DualSense Edge / Steam-Deck L4-L5-R4-R5), in
+    /// Moonlight's extended-button namespace (`input::gamepad::BTN_PADDLE1..4`, R4/L4/R5/L5).
+    /// Defined for wire completeness and pinned by the tests; `GamepadCapture.buttonMask` does not
+    /// read them yet — the GameController `paddleButton1..4` ↔ BTN_PADDLE physical correspondence
+    /// needs confirming on a real Elite pad first (see the gamepad-review-cleanup plan, G22), so
+    /// they are intentionally absent from `allButtons` until that forwarding lands.
+    public static let paddle1: UInt32 = 0x0001_0000
+    public static let paddle2: UInt32 = 0x0002_0000
+    public static let paddle3: UInt32 = 0x0004_0000
+    public static let paddle4: UInt32 = 0x0008_0000
 
+    /// Every button `buttonMask`/`sendGuide` can set — walked by `sync`'s transition diff and by
+    /// `flush` on release. Paddles are excluded until their capture lands (see above).
     public static let allButtons: [UInt32] = [
         dpadUp, dpadDown, dpadLeft, dpadRight, start, back,
         leftStickClick, rightStickClick, leftShoulder, rightShoulder, guide,
-        a, b, x, y, touchpadClick,
+        a, b, x, y, touchpadClick, misc1,
     ]
 
     public static let axisLSX: UInt32 = 0

clients/apple/Tests/PunktfunkKitTests/GamepadWireTests.swift

@@ -27,11 +27,16 @@ final class GamepadWireTests: XCTestCase {
         XCTAssertEqual(GamepadWire.x, 0x4000)
         XCTAssertEqual(GamepadWire.y, 0x8000)
         XCTAssertEqual(GamepadWire.touchpadClick, 0x10_0000)
+        XCTAssertEqual(GamepadWire.misc1, 0x0020_0000)
         // Every button is enumerated exactly once (releaseAll walks this list).
         let combined: UInt32 = GamepadWire.allButtons.reduce(0) { $0 | $1 }
-        XCTAssertEqual(combined, 0x0010_F7FF)
+        XCTAssertEqual(combined, 0x0030_F7FF)
-        XCTAssertEqual(GamepadWire.allButtons.count, 16)
+        XCTAssertEqual(GamepadWire.allButtons.count, 17)
         XCTAssertEqual(GamepadWire.allButtons.count, Set(GamepadWire.allButtons).count)
+        // Paddles are defined but not yet forwarded, so they stay out of allButtons for now.
+        for paddle in [GamepadWire.paddle1, GamepadWire.paddle2, GamepadWire.paddle3, GamepadWire.paddle4] {
+            XCTAssertFalse(GamepadWire.allButtons.contains(paddle))
+        }
         // Axis ids.
         XCTAssertEqual(GamepadWire.axisLSX, 0)
         XCTAssertEqual(GamepadWire.axisLSY, 1)
@@ -41,6 +46,42 @@ final class GamepadWireTests: XCTestCase {
         XCTAssertEqual(GamepadWire.axisRT, 5)
     }
 
+    func testButtonBitsMatchTheCABIVerbatim() {
+        // Assert EVERY wire constant against the generated C ABI header (punktfunk_core.h, the same
+        // source `punktfunk_core::input::gamepad` emits), so a Swift-side edit that drifts from the
+        // Rust contract fails CI — not just the handful spot-checked above. (Cross-cutting review
+        // finding G15: the button values were re-declared per client with only a 3-of-19 check.)
+        XCTAssertEqual(GamepadWire.dpadUp, UInt32(PUNKTFUNK_BTN_DPAD_UP))
+        XCTAssertEqual(GamepadWire.dpadDown, UInt32(PUNKTFUNK_BTN_DPAD_DOWN))
+        XCTAssertEqual(GamepadWire.dpadLeft, UInt32(PUNKTFUNK_BTN_DPAD_LEFT))
+        XCTAssertEqual(GamepadWire.dpadRight, UInt32(PUNKTFUNK_BTN_DPAD_RIGHT))
+        XCTAssertEqual(GamepadWire.start, UInt32(PUNKTFUNK_BTN_START))
+        XCTAssertEqual(GamepadWire.back, UInt32(PUNKTFUNK_BTN_BACK))
+        XCTAssertEqual(GamepadWire.leftStickClick, UInt32(PUNKTFUNK_BTN_LS_CLICK))
+        XCTAssertEqual(GamepadWire.rightStickClick, UInt32(PUNKTFUNK_BTN_RS_CLICK))
+        XCTAssertEqual(GamepadWire.leftShoulder, UInt32(PUNKTFUNK_BTN_LB))
+        XCTAssertEqual(GamepadWire.rightShoulder, UInt32(PUNKTFUNK_BTN_RB))
+        XCTAssertEqual(GamepadWire.guide, UInt32(PUNKTFUNK_BTN_GUIDE))
+        XCTAssertEqual(GamepadWire.a, UInt32(PUNKTFUNK_BTN_A))
+        XCTAssertEqual(GamepadWire.b, UInt32(PUNKTFUNK_BTN_B))
+        XCTAssertEqual(GamepadWire.x, UInt32(PUNKTFUNK_BTN_X))
+        XCTAssertEqual(GamepadWire.y, UInt32(PUNKTFUNK_BTN_Y))
+        XCTAssertEqual(GamepadWire.touchpadClick, UInt32(PUNKTFUNK_BTN_TOUCHPAD))
+        XCTAssertEqual(GamepadWire.misc1, UInt32(PUNKTFUNK_GAMEPAD_BTN_MISC1))
+        XCTAssertEqual(GamepadWire.paddle1, UInt32(PUNKTFUNK_GAMEPAD_BTN_PADDLE1))
+        XCTAssertEqual(GamepadWire.paddle2, UInt32(PUNKTFUNK_GAMEPAD_BTN_PADDLE2))
+        XCTAssertEqual(GamepadWire.paddle3, UInt32(PUNKTFUNK_GAMEPAD_BTN_PADDLE3))
+        XCTAssertEqual(GamepadWire.paddle4, UInt32(PUNKTFUNK_GAMEPAD_BTN_PADDLE4))
+        // Axis ids and pad count share the same header.
+        XCTAssertEqual(GamepadWire.axisLSX, UInt32(PUNKTFUNK_AXIS_LS_X))
+        XCTAssertEqual(GamepadWire.axisLSY, UInt32(PUNKTFUNK_AXIS_LS_Y))
+        XCTAssertEqual(GamepadWire.axisRSX, UInt32(PUNKTFUNK_AXIS_RS_X))
+        XCTAssertEqual(GamepadWire.axisRSY, UInt32(PUNKTFUNK_AXIS_RS_Y))
+        XCTAssertEqual(GamepadWire.axisLT, UInt32(PUNKTFUNK_AXIS_LT))
+        XCTAssertEqual(GamepadWire.axisRT, UInt32(PUNKTFUNK_AXIS_RT))
+        XCTAssertEqual(GamepadWire.maxPads, Int(MAX_PADS))
+    }
+
     func testPadIndexRidesFlagsOnEveryPerPadEvent() {
         // The wire pad index is the low byte of `flags` (punktfunk_core::input) on button + axis.
         let btn = PunktfunkInputEvent.gamepadButton(GamepadWire.a, down: true, pad: 3)