Phase C+8 — KeResetEvent canary-parity return value (sibling of C+7)
====================================================================

Scope: `crates/xenia-kernel/src/exports.rs`
LOC: ~12 body + ~80 test = ~92 net

Body change — `ke_reset_event` (~4160-4181):
--------------------------------------------

-fn ke_reset_event(ctx: &mut PpcContext, mem: &GuestMemory, state: &mut KernelState) {
-    let h = ctx.gpr[3] as u32;
-    ensure_dispatcher_object(state, mem, h);
-    let previous = match state.objects.get_mut(&h) {
-        Some(KernelObject::Event { signaled, .. }) => {
-            let prev = *signaled;
-            *signaled = false;
-            prev as u32
-        }
-        _ => 0,
-    };
-    ctx.gpr[3] = previous as u64;
-}
+fn ke_reset_event(ctx: &mut PpcContext, mem: &GuestMemory, state: &mut KernelState) {
+    // r3 = PKEVENT on Ke* (guest pointer). See `ensure_dispatcher_object`
+    // for the lazy-shadow step.
+    let h = ctx.gpr[3] as u32;
+    ensure_dispatcher_object(state, mem, h);
+    // Canary parity (xevent.cc:72-75): `XEvent::Reset` returns constant `1`
+    // on success — exact sibling of `XEvent::Set`. The NT contract claims
+    // the prior signaled state, but canary hardcodes `1` and the game
+    // observes that value via Phase A oracle at idx=102164. Sibling fix
+    // of Phase C+7 KeSetEvent (xevent.cc:60-64). The `assert_always;
+    // return 0` arm is preserved (no shadow -> 0).
+    let (previous, found) = match state.objects.get_mut(&h) {
+        Some(KernelObject::Event { signaled, .. }) => {
+            let prev = *signaled;
+            *signaled = false;
+            (prev as u32, true)
+        }
+        _ => (0u32, false),
+    };
+    state.audit_signal(h, ctx.lr as u32, "KeResetEvent", previous as u64);
+    ctx.gpr[3] = if found { 1 } else { 0 };
+}

Existing test (~5631-5647) comment-only update:
-----------------------------------------------

-        assert_eq!(ctx.gpr[3], 1, "previous state must be reported");
+        assert_eq!(ctx.gpr[3], 1, "canary parity: KeResetEvent returns constant 1 on hit");
   (plus updated doc explaining canary parity)

New tests added at module end (mirror of C+7's KeSetEvent block):
-----------------------------------------------------------------

    // Phase C+8 -- KeResetEvent canary-parity return value (sibling of C+7)
    1. ke_reset_event_returns_constant_one_on_unsignaled_manual_reset
       (this is THE Phase A oracle case -- prior state 0, canary returns 1)
    2. ke_reset_event_returns_constant_one_on_signaled_auto_reset
       (distinguish from prior-state-return bug: prior 1 == constant 1)
    3. ke_reset_event_returns_zero_on_missing_object
       (canary's `assert_always; return 0` arm -- invalid handle)
    4. nt_clear_event_resets_shadow_and_returns_status_success
       (already canary-parity; symmetry coverage)

`nt_clear_event` body: no change. Canary `NtClearEvent_entry` calls
`xeNtClearEvent` which uses `XEvent::Clear` (void return); already
returning STATUS_SUCCESS in ours.

Cascade outcome:
----------------
- A=verify canary's return: DONE, `1` confirmed from xevent.cc:72-75
- B=land fix: DONE
- C=main chain advances past 102164: DONE -- 102164 -> 102197 (+33)
- D=clean re-validation: DONE
- E=no escalation: DONE (12-LOC body change, additive tests only)

Next target: XamContentCreateEnumerator at tid=6->1 idx=102197
  canary return_value=1317 (0x525 = X_ERROR_NO_CONTENT)
  ours   return_value=0    (likely STATUS_SUCCESS or missing impl)