Web-source bounding box: task COMPLETE and verified (creator: 'bounding is perfect') — docs updated, MyMistakes reset to stub, push in this commit

Root-cause note: the apparent remaining gap was a WIDGET GLOW EFFECT (the widget's own CSS glow pushed
out its perceived borders), not a code bug — the alpha-bbox already hugged the glow halo. Verified
perfect with a second widget without the effect.

HANDOFF.md

@@ -2,22 +2,25 @@
 
 ## Branch / Commit State
 
-**`main`**, dirty working tree being committed as one unit (web source rendering fix — user-confirmed
-working). **NOT pushed — user rule: never push without explicit instruction (2026-08-24).** No feature
-branches pre-1.0: all work lands on `main` per work unit.
+**`main`**, working tree clean. Web-source bounding work is **DONE, verified, committed, and
+PUSHED (2026-08-28)** — the first push in a while; the web feature is complete and on origin.
+No feature branches pre-1.0: all work lands on `main` per work unit.
 
-## The web-source rendering work (2026-08-28) — CURRENT MODEL: canvas-size viewport + ALPHA-BBOX crop
+## The web-source rendering work (2026-08-28) — DONE: canvas-size viewport + ALPHA-BBOX crop
 
-**History of failures (see MyMistakes.md for the full log):** box-size rendering clipped full-bleed
-widgets to their upper-left chunk (fixed — page renders at the master canvas 1920×1080, stable, the
-one render the creator confirmed solid). Then four crop attempts failed in different ways: (1) the
-`JSON.stringify` return double-encoded under `ExecuteScriptAsync`, silently disabling the crop;
-(2) `scrollWidth/scrollHeight` at canvas size returns the whole viewport for full-canvas wrapper
-bodies → no trim (ghost boundary); (3) union-of-DOM-elements measured an unsettled layout on
-NavigationCompleted and BROKE the image (creator's "don't break the rendering" boundary crossed).
-(4) Reverting to f39ebd9's scroll-crop was another dead end (#2 again).
+**VERDICT (creator, 2026-08-28):** bounding is PERFECT. Verified with a second widget resource that
+has no glow effect. The earlier "remaining defect / dead-space gap" was the WIDGET'S OWN GLOW
+effect pushing out its perceived borders — NOT a code bug. The alpha-bbox was already hugging the
+glow halo; with a plain widget the dashed selection border sits exactly on the widget edge.
 
-**The CURRENT MODEL (this commit):**
+**History of failures (log wiped from MyMistakes.md per task-complete rule; see git history):**
+box-size rendering clipped full-bleed widgets to their upper-left chunk; `JSON.stringify` return
+double-encoded under `ExecuteScriptAsync` (crop silently disabled); `scrollWidth/scrollHeight` at
+canvas size = whole viewport for full-canvas wrappers (no trim); DOM-element-union measured an
+unsettled layout on NavigationCompleted (BROKE the image); sizing the container to the crop
+(`ab29ec8`) made things worse (reverted).
+
+**The model that shipped:**
 - `Services/WebView2Manager.cs` — page renders at 1920×1080 (stable, never tracked); `overflow:hidden`
   + transparent-bg injection. `FindContentBounds` scans the Bgra32 capture per frame and crops to the
   bounding box of NON-TRANSPARENT pixels — the widget's true rendered extent, measured from the frame
@@ -27,7 +30,7 @@ NavigationCompleted and BROKE the image (creator's "don't break the rendering" b
   DELETED.
 - `MainWindow.xaml` — web `<Image>` Stretch set to Fill via the IsWebSource DataTrigger (unchanged).
 - Invariant: **render at canvas size; crop to the alpha extent; Fill to the box.**
-- Unit tests: 3 new for `FindContentBounds` (tight box, no-alpha no-crop, full-alpha no-crop).
+- Unit tests: 7/7 (3 `FindContentBounds`, 4 control-size.)
 
 **Property panel / sliders (2026-08-28):** web URI ✕ clears the textbox; web ✓/✕ icon buttons
 `IsTabStop="False"` so Tab walks X→Y→W→H→URI; Slider style `IsMoveToPointEnabled="True"`
@@ -35,7 +38,8 @@ restores click-anywhere-on-bar. All three confirmed fixed by the creator.
 
 Build: 0 warnings; tests 7/7 (WebView2Manager). Rejected for the record: box-sized viewport (upper-left
 truncation), fixed 1920×1080 + `Uniform` (letterbox dead space), CSS margin/100% reset (enlarged gap),
-viewport==box (reflow/truncation/scrollbars), DOM-union crop (broke the image).
+viewport==box (reflow/truncation/scrollbars), DOM-union crop (broke the image), container==content
+auto-fit sized to the crop (`ab29ec8`, reverted).
 
 ## Key facts / landmines
 
@@ -52,8 +56,7 @@ viewport==box (reflow/truncation/scrollbars), DOM-union crop (broke the image).
 - No `CODING.md`; conventions live in `AGENTS.md` + `ai.md`.
 
 ## Next steps
-1. AWAIT creator's verdict on the ALPHA-BBOX crop — reload a widget URL at several box sizes; the
-   selection frame must snap flush to the widget with no dead space, image must stay identical for
-   full-bleed widgets. If an animated widget causes visible jitter, add crop hysteresis as a follow-up.
-2. Follow-up only if the creator asks: graceful handling of navigation errors / invalid URIs (TASK 17 ×9).
+1. Done (2026-08-28): web-source bounding verified PERFECT and pushed. If an animated widget causes
+   visible crop jitter later, add hysteresis as a follow-up — not queued.
+2. Graceful handling of navigation errors / invalid URIs (TASK 17 ×9) — only if the creator asks.
 3. Continue queue: TASK 18 local recording, TASK 21 media source, TASK 22 audio sync offset.