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/extract_canary_tid17_full.py

@@ -0,0 +1,117 @@
+#!/usr/bin/env python3
+"""Capture canary tid=17 (the sub_821748F0 worker) FULL timeline.
+Lifetime: 1.9378s to 2.0918s = 154ms.
+4140 events total. Compare to ours's tid=13 which has only 80 events before wedge.
+"""
+import json
+import os
+from collections import Counter
+
+INPUT = "/home/fabi/RE - Project Sylpheed/xenia-canary/build-cross/bin/Windows/Debug/canary-jitter-1.jsonl"
+OUTDIR = os.path.dirname(os.path.abspath(__file__))
+TARGET_TID = 17
+
+T_LO = 1_900_000_000
+T_HI = 2_200_000_000
+
+evts = []
+with open(INPUT, "r") as f:
+    for line in f:
+        if '"host_ns":' not in line:
+            continue
+        try:
+            i = line.index('"host_ns":') + len('"host_ns":')
+            j = i
+            while j < len(line) and (line[j].isdigit() or line[j] == '-'):
+                j += 1
+            host_ns = int(line[i:j])
+        except (ValueError, IndexError):
+            continue
+        if host_ns < T_LO:
+            continue
+        if host_ns >= T_HI:
+            break
+        if f'"tid":{TARGET_TID},' not in line:
+            continue
+        try:
+            ev = json.loads(line)
+        except json.JSONDecodeError:
+            continue
+        if ev.get("tid") != TARGET_TID:
+            continue
+        evts.append(ev)
+
+print(f"canary tid={TARGET_TID}: {len(evts)} events")
+if evts:
+    print(f"  first host_ns: {evts[0]['host_ns']/1e9:.4f}s")
+    print(f"  last host_ns: {evts[-1]['host_ns']/1e9:.4f}s")
+
+# Top kernel calls.
+sum_calls = Counter()
+for ev in evts:
+    if ev["kind"] == "kernel.call":
+        sum_calls[ev["payload"].get("name", "?")] += 1
+
+print(f"\n=== Top kernel.calls ({len(sum_calls)} unique) ===")
+for n, c in sum_calls.most_common(40):
+    print(f"  {c:5d}  {n}")
+
+# Save timeline.
+with open(os.path.join(OUTDIR, f"canary-tid{TARGET_TID}-worker-timeline.csv"), "w") as f:
+    f.write("host_ns,tid_event_idx,kind,name,detail\n")
+    for ev in evts:
+        name = ev["payload"].get("name", "")
+        detail = json.dumps(ev["payload"])[:400].replace('"', '""')
+        f.write(f'{ev["host_ns"]},{ev["tid_event_idx"]},{ev["kind"]},{name},"{detail}"\n')
+
+# Compare against ours tid=13.
+print("\n=== Now comparing ours tid=13 ===")
+OURS_INPUT = "/home/fabi/RE - Project Sylpheed/xenia-rs/audit-runs/phase-w-wedge-reattack/ours-postfix.jsonl"
+ours_evts = []
+with open(OURS_INPUT, "r") as f:
+    for line in f:
+        if f'"tid":13' not in line:
+            continue
+        try:
+            ev = json.loads(line)
+        except json.JSONDecodeError:
+            continue
+        if ev.get("tid") != 13:
+            continue
+        ours_evts.append(ev)
+
+print(f"ours tid=13: {len(ours_evts)} events")
+if ours_evts:
+    print(f"  first host_ns: {ours_evts[0]['host_ns']/1e9:.4f}s")
+    print(f"  last host_ns: {ours_evts[-1]['host_ns']/1e9:.4f}s")
+
+ours_sum = Counter()
+for ev in ours_evts:
+    if ev["kind"] == "kernel.call":
+        ours_sum[ev["payload"].get("name", "?")] += 1
+
+print(f"\n=== ours tid=13 kernel.calls ({len(ours_sum)} unique) ===")
+for n, c in ours_sum.most_common(40):
+    print(f"  {c:5d}  {n}")
+
+# Differential table.
+all_names = set(sum_calls.keys()) | set(ours_sum.keys())
+print(f"\n=== Differential canary tid=17 vs ours tid=13 ===")
+print(f"{'kernel.call':<45s} {'canary':>8s} {'ours':>8s} {'delta':>8s}")
+diffs = []
+for n in sorted(all_names):
+    cc = sum_calls.get(n, 0)
+    oc = ours_sum.get(n, 0)
+    diffs.append((cc - oc, n, cc, oc))
+diffs.sort(key=lambda x: -abs(x[0]))
+for delta, n, cc, oc in diffs[:80]:
+    print(f"  {n:<45s} {cc:>8d} {oc:>8d} {delta:>+8d}")
+
+with open(os.path.join(OUTDIR, "differential-canary-tid17-vs-ours-tid13.txt"), "w") as f:
+    f.write(f"Differential canary tid=17 (sub_821748F0 worker) vs ours tid=13\n\n")
+    f.write(f"canary tid=17 total events: {len(evts)}, ours tid=13 total: {len(ours_evts)}\n")
+    f.write(f"canary tid=17 duration: 1.9378s..2.0918s (154ms, terminates)\n")
+    f.write(f"ours tid=13 duration: until wedge, never terminates\n\n")
+    f.write(f"{'kernel.call':<45s} {'canary':>8s} {'ours':>8s} {'delta':>8s}\n")
+    for delta, n, cc, oc in diffs:
+        f.write(f"  {n:<45s} {cc:>8d} {oc:>8d} {delta:>+8d}\n")