handoff: VSync/event-wedge fixes + iterate 2.A–2.BC research notes

Source changes (dormant parity infra, retained from iterate 2.AI/2.AO):
- xenia-kernel/exports.rs: nt_create_event manual_reset polarity +
  related event wiring
- xenia-gpu/mmio_region.rs: D1MODE_VBLANK_VLINE_STATUS hardcode parity

Also lands the audit-runs/ analysis notes (.md/.txt/.json digests) for the
iterate 2.x VSync/0x10e8/0x1004 wedge investigation. Raw trace dumps
(.jsonl/.gz/.csv/.stdout) and agent worktrees (.claude/) are gitignored as
regenerable local artifacts — see memory + HANDOFF for the running findings.

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

audit-runs/review-a-step2-natural-trigger/ours-tid1-summary

@@ -0,0 +1,87 @@
+Ours tid=1 summary
+
+Total kernel.call: 36136
+Last tid_event_idx: 108506
+Last host_ns: 1727614433 (1.728 s)
+
+=== Top kernel.call by frequency ===
+   17834  RtlEnterCriticalSection
+   17834  RtlLeaveCriticalSection
+      65  RtlInitializeCriticalSectionAndSpinCount
+      33  KeRaiseIrqlToDpcLevel
+      29  RtlInitializeCriticalSection
+      27  KeAcquireSpinLockAtRaisedIrql
+      27  KeReleaseSpinLockFromRaisedIrql
+      26  KfLowerIrql
+      22  NtClose
+      20  NtWriteFile
+      19  NtCreateEvent
+      17  RtlInitAnsiString
+      14  NtSetEvent
+      13  NtWaitForSingleObjectEx
+      11  MmAllocatePhysicalMemoryEx
+       9  RtlNtStatusToDosError
+       9  ExCreateThread
+       9  NtDuplicateObject
+       8  NtCreateFile
+       8  NtReleaseSemaphore
+       7  NtQueryFullAttributesFile
+       5  KeQueryPerformanceFrequency
+       3  KeGetCurrentProcessType
+       3  NtOpenFile
+       3  KeEnterCriticalRegion
+       3  KeLeaveCriticalRegion
+       3  NtCreateSemaphore
+       3  KeSetBasePriorityThread
+       3  ObReferenceObjectByHandle
+       3  ObDereferenceObject
+       2  RtlImageXexHeaderField
+       2  NtAllocateVirtualMemory
+       2  XexCheckExecutablePrivilege
+       2  KeTlsAlloc
+       2  KeTlsSetValue
+       2  KeQuerySystemTime
+       2  NtReadFile
+       2  NtDeviceIoControlFile
+       2  NtQueryVolumeInformationFile
+       2  MmFreePhysicalMemory
+       2  VdInitializeEngines
+       2  ExRegisterTitleTerminateNotification
+       2  ExGetXConfigSetting
+       2  VdSetSystemCommandBufferGpuIdentifierAddress
+       2  VdQueryVideoMode
+       2  VdQueryVideoFlags
+       2  VdRetrainEDRAM
+       2  NtResumeThread
+       2  KeResumeThread
+       1  XGetAVPack
+       1  XeCryptSha
+       1  XeKeysConsolePrivateKeySign
+       1  XamTaskSchedule
+       1  XamTaskCloseHandle
+       1  KeWaitForSingleObject
+       1  KeResetEvent
+       1  XamContentCreateEnumerator
+       1  XamNotifyCreateListener
+       1  VdShutdownEngines
+       1  VdSetGraphicsInterruptCallback
+       1  MmGetPhysicalAddress
+       1  VdInitializeRingBuffer
+       1  VdEnableRingBufferRPtrWriteBack
+       1  KiApcNormalRoutineNop
+       1  VdCallGraphicsNotificationRoutines
+       1  VdRetrainEDRAMWorker
+       1  VdIsHSIOTrainingSucceeded
+       1  VdGetSystemCommandBuffer
+       1  VdSwap
+       1  VdGetCurrentDisplayGamma
+       1  VdSetDisplayMode
+       1  VdGetCurrentDisplayInformation
+       1  RtlFillMemoryUlong
+       1  VdInitializeScalerCommandBuffer
+       1  VdPersistDisplay
+       1  KeInitializeSemaphore
+       1  XAudioRegisterRenderDriverClient
+
+=== Unique kernel.call names ===
+  77