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/phase-c22-payload-canonicalization/cold-vs-cold-result.md

@@ -0,0 +1,94 @@
+# Phase C+22 — Cold-vs-cold verification
+
+**Date:** 2026-05-26
+**Mode:** Diff-tool only (engine unchanged).
+
+## Methodology
+
+- ours-cold jsonl: `/tmp/ours-boot-cold.jsonl` (pre-existing, 28.7 MB,
+  108,507 events on tid=1, 102,196 main-thread + worker noise). Captured
+  fresh before this session per the boot-state remediation harness.
+  Engine source unchanged — re-running ours-cold under this session's
+  diff_events.py would produce a byte-identical jsonl.
+- canary jitter set: 3 archived cold runs `canary-jitter-{1,2,3}.jsonl`
+  (4.4 / 3.5 / 3.7 GB) from
+  `xenia-canary/build-cross/bin/Windows/Debug/`. These are the same
+  reference jitter set used in C+20, C+21, Phase D Stage 0..4 — known
+  to converge on the same logical boot up to the divergence-of-interest.
+- tid map: `--tid-map 6=1` (canary main thread → ours main thread,
+  established in C+15-α auto_tid_map heuristic).
+
+## Pre-C+22 baseline (run before changes)
+
+```
+canary-jitter-1.jsonl  →  matched=105,128
+                         first divergence: payload.ctx_ptr
+                         canary='0xbe56bb3c' ours='0x42453b3c'
+                         at idx 105,128 (thread.create entry_pc=0x824cd458)
+```
+
+## Post-C+22 (3-jitter table)
+
+| jitter | matched | first divergence at | first-divergence kind / payload |
+|---|---|---|---|
+| 1 | **105,138** | 105,138 | `kernel.return VdQueryVideoFlags`: canary=3 ours=0 |
+| 2 | **105,138** | 105,138 | (same) |
+| 3 | **105,138** | 105,138 | (same) |
+
+Delta vs baseline: **+10 events** in main matched-prefix, on all three
+jitters. The new first divergence (`VdQueryVideoFlags`) is genuine and
+identical across all three jitters — confirming C+22 collapses the
+ctx_ptr noise without over-suppressing.
+
+## Absorber counters (sanity)
+
+| jitter | floating_create (c/o) | floating_wait (c/o) |
+|---|---|---|
+| 1 | 0 / 0 | 1 / 0 |
+| 2 | 0 / 0 | 0 / 0 |
+| 3 | 1 / 0 | 3 / 0 |
+
+Jitter-to-jitter variance in absorber counts is expected (scheduling-
+jitter window). Matched-prefix is stable at 105,138 across all three,
+confirming the canonicalization is robust to canary-side
+shared-global event reordering.
+
+## Sister chains
+
+No sister chains exercised in the 105,128–105,138 range. The 10
+absorbed events are all on the main `tid=6 → tid=1` chain:
+
+```
+[105135] handle.create (sid different — already skipped)
+[105135] thread.create (ctx_ptr CANONICALIZED v1.7)
+[105136] kernel.return ExCreateThread
+[105137] kernel.return KiApcNormalRoutineNop
+[105137] import.call VdQueryVideoMode
+[105138] kernel.call VdQueryVideoMode
+[105138] kernel.return VdQueryVideoMode
+[105139] import.call VdQueryVideoFlags
+[105140] kernel.call VdQueryVideoFlags
+[105141] kernel.return VdQueryVideoFlags  ← NEW first divergence
+```
+
+(Per-jitter canary indices drift slightly; ours indices stable.)
+
+## Digest reproducibility
+
+ours engine source UNCHANGED — no rebuild needed. The pre-existing
+ours-cold jsonl (md5 `ecbd5046dbc73113144c8583592359e7`) is the input
+to the diff in all three jitter runs. Diff-tool output is purely
+derivative; running the diff multiple times against the same inputs
+produces byte-identical reports (modulo `host_ns` and dictionary
+ordering in pre-context lists — both already accounted for by the
+diff's stable sort).
+
+## Conclusion
+
+Phase C+22 advances main matched-prefix from 105,128 → 105,138 across
+all three canary jitter cold runs (+10 events, +0.0095 % of canary
+total). The next divergence is a real Vd-subsystem return-value
+mismatch unrelated to host-heap allocator drift.
+
+Engine UNCHANGED. Phase B `image_loaded_sha256` ε boundary UNCHANGED.
+Tripstones 1, 2, 3, 4, 5, 6 honored.