fix(fmt) + feat(gamepad): CI-matching rustfmt everywhere, enforced by repo git hooks; N4 spike flips to GO via MI_02

Three things that belong together:

1. rustfmt the gamepad-new-types host files ci.yml's `cargo fmt --all
   --check` gate flags (the .21/.133 verify recipes ran clippy+tests
   but never fmt — the same class of miss as 69f30f30).

2. Enforce it at the source: scripts/git-hooks/{pre-commit,pre-push}
   run the exact CI fmt gates (main workspace + the shipped-driver
   crates of the UMDF workspace); CONTRIBUTING documents the one-time
   `git config core.hooksPath scripts/git-hooks`. pre-push is the
   enforcement point (plumbing commits bypass pre-commit).

3. N4 follow-up — the spike verdict FLIPS TO GO: SwDeviceProfile grows
   `usb_mi`, synthesizing `&MI_02` into the Deck spike's USB hardware
   ids. hidclass mirrors the parent's USB tokens into the HID child's
   hardware ids, and hidapi/SDL/Steam parse `MI_` as bInterfaceNumber
   (defaulting to 0 when absent — the exact gate the first run hit:
   Steam wants the Deck controller on interface 2). Re-run live on
   .173: Steam logs `Interface: 2`, then `!! Steam controller device
   opened`, `Steam Controller reserving XInput slot 0`, and activates
   a mapping — full Steam Input promotion of the software-devnode
   Deck, no driver change needed. The PS identities pass
   `usb_mi: None` (real single-interface devices carry no MI_ token).
   A proper Windows-Deck backend phase is now justified; planned
   separately.

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

crates/punktfunk-host/src/inject/linux/dualsense.rs

@@ -13,10 +13,9 @@
 //! UMDF-driver backend; this module is just the `/dev/uhid` plumbing around it.
 
 use super::dualsense_proto::{
-    edge_paddle_bits, parse_ds_output, serialize_state, DsFeedback, DsState,
-    DS_EDGE_PRODUCT, DS_FEATURE_CALIBRATION, DS_FEATURE_FIRMWARE, DS_FEATURE_PAIRING,
-    DS_INPUT_REPORT_LEN, DS_PRODUCT, DS_TOUCH_H, DS_TOUCH_W, DS_VENDOR, DUALSENSE_EDGE_RDESC,
-    DUALSENSE_RDESC,
+    edge_paddle_bits, parse_ds_output, serialize_state, DsFeedback, DsState, DS_EDGE_PRODUCT,
+    DS_FEATURE_CALIBRATION, DS_FEATURE_FIRMWARE, DS_FEATURE_PAIRING, DS_INPUT_REPORT_LEN,
+    DS_PRODUCT, DS_TOUCH_H, DS_TOUCH_W, DS_VENDOR, DUALSENSE_EDGE_RDESC, DUALSENSE_RDESC,
 };
 use crate::inject::uhid_manager::{PadFeedback, PadProto, UhidManager};
 use anyhow::{Context, Result};
@@ -102,7 +101,8 @@ impl DualSensePad {
                 format!("open {UHID_PATH} (is the 60-punktfunk.rules uhid rule installed + are you in 'input'?)")
             })?;
         let mut ds = DualSensePad { fd, seq: 0, ts: 0 };
-        ds.send_create2(index, id).context("UHID_CREATE2 DualSense")?;
+        ds.send_create2(index, id)
+            .context("UHID_CREATE2 DualSense")?;
         Ok(ds)
     }
 

crates/punktfunk-host/src/inject/linux/switch_pro.rs

@@ -84,7 +84,12 @@ impl SwitchProPad {
         let mut ev = [0u8; UHID_EVENT_SIZE];
         ev[0..4].copy_from_slice(&UHID_CREATE2.to_ne_bytes());
         // union (uhid_create2_req) starts at byte 4.
-        put_cstr(&mut ev, 4, 128, &format!("Punktfunk Switch Pro Controller {index}")); // name[128]
+        put_cstr(
+            &mut ev,
+            4,
+            128,
+            &format!("Punktfunk Switch Pro Controller {index}"),
+        ); // name[128]
         put_cstr(&mut ev, 132, 64, &format!("punktfunk/switchpro/{index}")); // phys[64]
         put_cstr(&mut ev, 196, 64, &format!("punktfunk-swpro-{index}")); // uniq[64]
         ev[260..262].copy_from_slice(&(PROCON_RDESC.len() as u16).to_ne_bytes()); // rd_size
@@ -123,7 +128,13 @@ impl SwitchProPad {
         let reply = match id {
             // Device info — the fatal one (probe aborts without it): type = Pro Controller +
             // this pad's virtual MAC. Real hardware acks it with 0x82.
-            0x02 => build_subcmd_reply(&st, self.timer, 0x82, id, &device_info_payload(&switch_mac(self.index))),
+            0x02 => build_subcmd_reply(
+                &st,
+                self.timer,
+                0x82,
+                id,
+                &device_info_payload(&switch_mac(self.index)),
+            ),
             // SPI flash read: echoed addr + len + the canned calibration bytes. An unmapped
             // range answers zeroes (echoed header, zero data) — the driver then warns and uses
             // its defaults instead of stalling through 2 × 1 s timeouts.
@@ -134,7 +145,11 @@ impl SwitchProPad {
                     .unwrap_or(0);
                 let len = args.get(4).copied().unwrap_or(0);
                 let payload = spi_flash_read(addr, len).unwrap_or_else(|| {
-                    tracing::debug!(addr = format!("{addr:#x}"), len, "unmapped SPI read — zero fill");
+                    tracing::debug!(
+                        addr = format!("{addr:#x}"),
+                        len,
+                        "unmapped SPI read — zero fill"
+                    );
                     let mut p = Vec::with_capacity(5 + len as usize);
                     p.extend_from_slice(&addr.to_le_bytes());
                     p.push(len);

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

@@ -404,7 +404,7 @@ pub fn sc_from_gamepad(
     // SC grips at the Deck's L5/R5 bit positions (9.7 / 10.0): the wire primary pair L4/R4.
     set(&mut b, on(gs::BTN_PADDLE2), btn::L5); // left grip
     set(&mut b, on(gs::BTN_PADDLE1), btn::R5); // right grip
-    // Joystick click (10.6 — the bit the Deck calls L3) + right-pad click (10.2).
+                                               // Joystick click (10.6 — the bit the Deck calls L3) + right-pad click (10.2).
     set(&mut b, on(gs::BTN_LS_CLICK), btn::L3);
     set(
         &mut b,
@@ -444,7 +444,7 @@ pub fn serialize_sc_state(r: &mut [u8; STEAM_REPORT_LEN], st: &SteamState, seq:
     r[10] = ((buttons >> 16) & 0xFF) as u8;
     r[11] = (st.lt >> 7).min(255) as u8; // left trigger, u8
     r[12] = (st.rt >> 7).min(255) as u8; // right trigger, u8
-    // Bytes 16..20 carry EITHER the joystick OR the left pad, per the 10.3 touched bit.
+                                         // Bytes 16..20 carry EITHER the joystick OR the left pad, per the 10.3 touched bit.
     let (x, y) = if buttons & btn::LPAD_TOUCH != 0 {
         (st.lpad_x, st.lpad_y)
     } else {
@@ -824,11 +824,7 @@ mod tests {
     fn sc_serialize_and_mapping() {
         // Full mapping: face + grips + clicks + a deflected right stick.
         let s = sc_from_gamepad(
-            gs::BTN_A
-                | gs::BTN_PADDLE1
-                | gs::BTN_PADDLE2
-                | gs::BTN_LS_CLICK
-                | gs::BTN_RS_CLICK,
+            gs::BTN_A | gs::BTN_PADDLE1 | gs::BTN_PADDLE2 | gs::BTN_LS_CLICK | gs::BTN_RS_CLICK,
             1000,
             -2000,
             3000,

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

@@ -486,7 +486,7 @@ mod tests {
     fn pack12_layout() {
         assert_eq!(pack12(0x578, 0x578), [0x78, 0x85, 0x57]); // 1400/1400 (the cal pair)
         assert_eq!(pack12(0x800, 0x800), [0x00, 0x08, 0x80]); // 2048/2048 (the center pair)
-        // Extract back: a = b0 | (b1 & 0xF) << 8; b = (b1 >> 4) | b2 << 4.
+                                                              // Extract back: a = b0 | (b1 & 0xF) << 8; b = (b1 >> 4) | b2 << 4.
         let p = pack12(0xABC, 0x123);
         let a = p[0] as u16 | ((p[1] as u16 & 0xF) << 8);
         let b = ((p[1] as u16) >> 4) | ((p[2] as u16) << 4);

crates/punktfunk-host/src/inject/windows/dualsense_windows.rs

@@ -88,6 +88,11 @@ pub(super) struct SwDeviceProfile<'a> {
     pub hwid: &'a str,
     /// The USB VID&PID token (`VID_054C&PID_0CE6`) used to synthesize the USB hardware/compatible ids.
     pub usb_vid_pid: &'a str,
+    /// USB composite interface number to synthesize (`&MI_xx` appended to the USB hardware ids).
+    /// hidclass mirrors the parent's `USB\VID…` tokens into the HID child's hardware ids, and
+    /// hidapi/SDL/Steam parse the child's `MI_` token as `bInterfaceNumber` (defaulting to 0 when
+    /// absent) — the Steam Deck's controller lives on interface 2, the gate the N4 spike hit.
+    pub usb_mi: Option<u8>,
     /// Device description shown in Device Manager.
     pub description: &'a str,
 }
@@ -126,8 +131,9 @@ pub(super) fn create_swdevice(p: &SwDeviceProfile) -> Result<(HSWDEVICE, Option<
             .chain(std::iter::once(0))
             .collect()
     };
-    let usb_rev = format!("USB\\{}&REV_0100", p.usb_vid_pid);
-    let usb = format!("USB\\{}", p.usb_vid_pid);
+    let mi = p.usb_mi.map(|n| format!("&MI_{n:02}")).unwrap_or_default();
+    let usb_rev = format!("USB\\{}&REV_0100{mi}", p.usb_vid_pid);
+    let usb = format!("USB\\{}{mi}", p.usb_vid_pid);
     let hwids = multi_sz(&[
         p.hwid, // FIRST → the INF binds our UMDF driver on this id
         usb_rev.as_str(),
@@ -297,6 +303,7 @@ impl DsWinPad {
             container_index: index,
             hwid: id.hwid,
             usb_vid_pid: id.usb_vid_pid,
+            usb_mi: None, // single-interface USB devices (real DS/Edge have no MI_ token)
             description: id.description,
         }) {
             Ok((h, i)) => (Some(h), i),
@@ -498,6 +505,9 @@ pub fn deck_spike_hold(index: u8, secs: u64) -> Result<()> {
         container_index: index,
         hwid: "pf_steamdeck",
         usb_vid_pid: "VID_28DE&PID_1205",
+        // The Deck's controller interface — the promotion gate the first spike run hit
+        // (hidapi parses MI_ from the child hwids; absent = interface 0, Steam wants 2).
+        usb_mi: Some(2),
         description: "punktfunk Virtual Steam Deck (spike)",
     })?;
     let _sw = super::gamepad_raii::SwDevice::new(hsw);
@@ -515,9 +525,8 @@ pub fn deck_spike_hold(index: u8, secs: u64) -> Result<()> {
         channel.pump();
         // Log any feature/output traffic Steam sends — each one is spike evidence.
         // SAFETY: base points at SHM_SIZE bytes; OFF_OUT_SEQ is in range.
-        let seq = unsafe {
-            std::ptr::read_unaligned(channel.data_base().add(OFF_OUT_SEQ) as *const u32)
-        };
+        let seq =
+            unsafe { std::ptr::read_unaligned(channel.data_base().add(OFF_OUT_SEQ) as *const u32) };
         if seq != last_out_seq {
             last_out_seq = seq;
             let mut out = [0u8; 16];

crates/punktfunk-host/src/inject/windows/dualshock4_windows.rs

@@ -64,6 +64,7 @@ impl Ds4WinPad {
             container_index: index,
             hwid: "pf_dualshock4",
             usb_vid_pid: "VID_054C&PID_09CC",
+            usb_mi: None,
             description: "punktfunk Virtual DualShock 4",
         }) {
             Ok((h, id)) => (Some(h), id),