From c46f3a11683e96c51857e7991034ea8e3aa78b28 Mon Sep 17 00:00:00 2001
From: gramps <gramps@llamachile.shop>
Date: Fri, 4 Sep 2026 12:37:26 -0700
Subject: [PATCH] =?UTF-8?q?docs:=20HANDOFF=20=E2=80=94=20de-duplicate=20th?=
 =?UTF-8?q?e=20sliced-6/7=20history=20paragraph?=
MIME-Version: 1.0
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---
 HANDOFF.md | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/HANDOFF.md b/HANDOFF.md
index 19a9bc9..1b2215e 100644
--- a/HANDOFF.md
+++ b/HANDOFF.md
@@ -52,14 +52,14 @@ RealApp boot-smoke. Scope-check passed.
    not cache keys. Tests: `PasteCache_...` + 85/85 across compositor/pump/chat/capture/session
    classes; clean build 0 warnings. (Cam bypasses the cache via IsOpaque; revisit if take 9 is
    borderline. Follow-ups unchanged: vertical-tier alloc, debounced chat re-render on bursts.)
-3. **Take 9/10 + slices 6-7 (2026-09-04):** slice 6 broke the 15.6ms Task.Delay sleep quantum (timeBeginPeriod + bulk-sleep + 2ms spin tail + wait stat); take 10's `wait 10ms after render 22ms` then exposed the FINAL structural bug: the pump loop's await-continuations inherited the UI SynchronizationContext — the "WPF-free" producer had been rendering ON THE DISPATCHER, queued behind the live preview, the whole time (explains every 'zero change' complaint). Slice 7: Task.Run the loop (OBS pattern) + StaticPixelCache lock + chat raster-miss marshalled to dispatcher + SustainedLowLatency GC + `worst render` stat + webcam through paste cache. Test `Pump_Produces_OffTheStartingContext`. 70/70 green, clean build. paste cache moved render 26.5→22.4ms yet
-   period stayed ~37ms — the gap is Task.Delay's ~15.6ms Windows sleep quantum padding every sub-tick
-   wait. **This is why takes 7→9 read as "zero change" despite real wins: the sleep floor dominated.**
-   Fixed (media-app canon, cited in code + MyMistakes #3): timeBeginPeriod(1) for the pump's life
-   (paired End in finally), sleep the bulk, SPIN the last 2ms across the deadline; stats gained
-   `avg wait` so render+submit+wait ≈ period (accounting closed — nothing can hide). Webcam now
-   routes through the paste cache too (bypass re-sampled 156k px even between identical device
-   frames). 52/52 per-class green, clean build 0 warnings, committed this slice.
+3. **Slices 6-7 (2026-09-04, committed):** slice 6 broke the 15.6ms Task.Delay sleep quantum
+   (timeBeginPeriod + bulk-sleep + 2ms spin tail + `avg wait` stat — the quantum had capped the
+   producer at ~27fps and made two real render wins read as "zero change"). Slice 7 then resolved
+   take 10's impossible math (`render 22 + wait 10` vs a 16.7 deadline): the pump's continuations
+   inherited the UI SynchronizationContext — the loop had been rendering on the dispatcher behind
+   the live preview the whole saga. Task.Run the loop (OBS pattern), StaticPixelCache locked, chat
+   raster-miss marshalled to the dispatcher, SustainedLowLatency GC, `worst render` stat, webcam
+   through the paste cache. Tests Pump_Paces/Pump_Produces_OffTheStartingContext; 70/70 green.
 4. **Take 11 ran + slice 8 (2026-09-04, committed with the audio unit below):** off-UI loop
    WORKED — typical frames land exactly on the deadline (work ~10 + wait ~6.8 = 16.7; 212/300).
    Remaining gap = periodic 35-65ms spikes growing across the take = gen2 GC pauses; the capture