fix(host/inject,drivers): rumble root fixes A-C — lossless report ring + rumble-keyed idle watchdogs

B: PadFeedback.game_drove -> rumble_drove, keyed on vibration-asserting reports — an
LED/adaptive-trigger stream can no longer feed the abandoned-rumble force-off while a
coalesced stop never re-asserts (the confirmed unbounded stuck-ON path). C: Linux parity —
every UHID backend now arms the shared watchdog (Steam Input drives these pads over hidraw
with Windows abandonment semantics) and the uinput mixer force-stops abandoned
infinite-replay FF effects (FfState, unit-tested). Shared PUNKTFUNK_RUMBLE_IDLE_MS hatch
(0 = off; non-zero floored above SDL's ~2 s rumble resend).

A: PadShm v2.1 — a 1024 B tail extension carrying an 8-slot lossless output-report ring,
feature-negotiated via zeroed reserved fields (out_ring_ver; deliberately NO
GAMEPAD_PROTO_VERSION bump — mixed generations degrade to the legacy latest-report slot
instead of failing closed). The pf-dualsense driver dual-writes both planes
(publish_output); the host's shared OutputDrain drains oldest->newest with a torn-read
recheck and an overflow->resync path (PadFeedback.resync force-stops + re-arms dedups).
pf-umdf-util grows a min_data_size map fallback. Ds*Feedback.fresh removed (dead).

design/rumble-root-fix.md par. A-C. Verified: pf-inject tests+clippy Linux+Windows (53/53
on winbox incl. the stop-coalesce repro); drivers ws check+clippy on the CI runner.

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

crates/pf-inject/src/inject/proto/dualsense_proto.rs

@@ -469,10 +469,10 @@ pub struct DsFeedback {
     pub hidout: Vec<HidOutput>,
     /// `(low, high)` motor levels (0..=0xFFFF), if a report carried them.
     pub rumble: Option<(u16, u16)>,
-    /// Whether a fresh output report was seen this poll (set by the backend's section poll, not by
-    /// the parser) — the game-activity signal the [`UhidManager`](crate::uhid_manager)
-    /// abandoned-rumble force-off keys on.
-    pub fresh: bool,
+    /// The driver's output-report ring overflowed this poll — pending reports were DISCARDED and
+    /// feedback state is unknown; the [`UhidManager`](crate::uhid_manager) must resync (silence +
+    /// re-armed dedups). Set by the backend's section drain, never by the parser.
+    pub resync: bool,
 }
 
 /// Parse a DualSense USB output report (`0x02`) into a [`DsFeedback`]. The byte layout below is
@@ -728,6 +728,17 @@ mod tests {
         assert!(fb.rumble.is_none());
         assert_eq!(fb.hidout.len(), 1);
         assert!(matches!(fb.hidout[0], HidOutput::Led { r: 1, .. }));
+
+        // An explicit stop — vibration flag SET, motors zero — parses as `Some((0, 0))`, never as
+        // absence: this is what distinguishes "the game stopped the motors" from "this report says
+        // nothing about rumble", and what `rumble_drove` (the abandoned-rumble watchdog's activity
+        // signal) keys on.
+        let mut data = vec![0u8; 48];
+        data[0] = 0x02;
+        data[1] = 0x03; // compatible vibration + haptics select
+        let mut fb = DsFeedback::default();
+        parse_ds_output(0, &data, &mut fb);
+        assert_eq!(fb.rumble, Some((0, 0)));
     }
 
     /// The input report's sensor/touch bytes must land exactly where the kernel's