fix(desktop): preserve layered PPTX backgrounds (#6845) (#7106)

* fix(desktop): preserve layered PPTX backgrounds

* fix(desktop): constrain layered PPTX rasterization

Keep unsupported gradients and static nested panels on their authored elements, and avoid duplicating the slide background shim when Chromium capture owns the layer.\n\nGenerated-By: looper 0.11.8 (runner=fixer, agent=codex)

* fix(desktop): preserve layered panel edge cases

Generated-By: looper 0.11.8 (runner=fixer, agent=codex)

* fix(desktop): preserve pseudo and masked PPTX layers

Generated-By: looper 0.11.8 (runner=fixer, agent=codex)

* fix(desktop): preserve composed PPTX background layers

Generated-By: looper 0.11.8 (runner=fixer, agent=codex)

* test(desktop): batch layered PPTX export probe

Generated-By: looper 0.11.8 (runner=fixer, agent=codex)

* test(desktop): consolidate layered PPTX probe slide

Generated-By: looper 0.11.8 (runner=fixer, agent=codex)

* test(desktop): terminate layered PPTX probe cleanly

Generated-By: looper 0.11.8 (runner=fixer, agent=codex)

* fix(desktop): preserve layered PPTX capture visibility and order

Filter Chromium capture targets to rendered slide intersections, and keep rasterized ::before backgrounds below native pseudo content. Extend the Electron export fixture and give its Linux subprocess enough concurrent-run budget.

Generated-By: looper 0.11.8 (runner=fixer, agent=codex)

* test(desktop): expose layered PPTX probe stage

Emit the active Electron renderer stage so CI-side subprocess timeouts identify the blocked boundary instead of returning an empty error.

Generated-By: looper 0.11.8 (runner=fixer, agent=codex)

* test(desktop): paint layered PPTX probe window

Mirror the production transparent showInactive lifecycle so requestAnimationFrame advances under Linux/Xvfb. Restore the original probe budgets and remove temporary stage diagnostics.

Generated-By: looper 0.11.8 (runner=fixer, agent=codex)

* fix(desktop): layer slide backgrounds below pseudos

Reserve explicit and captured slide-background sort slots below rasterized ::before layers so opaque slide fills cannot hide authored gradients. Cover the slide-root pattern with decoded PNG and PPTX media-order assertions.

Generated-By: looper 0.11.8 (runner=fixer, agent=codex)

* fix(desktop): keep layered PPTX captures background-only

Order positive-z ::after background captures below native pseudo content, and suppress replaced foreground objects only while Chromium captures their layered backgrounds.

Generated-By: looper 0.11.8 (runner=fixer, agent=codex)

* fix(desktop): flatten blended PPTX backgrounds

Preserve the authored backdrop while Chromium captures non-normal blend layers, including materialized pseudo-element backgrounds, and verify the resulting multiply-composited PPTX pixel.

Generated-By: looper 0.11.8 (runner=fixer, agent=codex)

* fix(desktop): preserve blended PPTX backdrops

Keep preceding sibling and ancestor pseudo backgrounds visible while Chromium flattens non-normal blend layers, without capturing their foreground content. Extend the real Electron export fixture with a layered pseudo backdrop pixel assertion.

Generated-By: looper 0.11.8 (runner=fixer, agent=codex)

* fix(desktop): preserve composited PPTX capture fidelity

Normalize the export DOM before Chromium measures layered backgrounds, flatten backdrop-filter dependencies, and preserve per-layer background blending for pseudo captures. Extend the Electron export probe with geometry and decoded-pixel regressions.

Generated-By: looper 0.11.8 (runner=fixer, agent=codex)

* test(desktop): tolerate Chromium color rounding

Allow a one-level RGB tolerance for backdrop-filter output so platform-specific Chromium quantization does not fail an otherwise faithful export.

Generated-By: looper 0.11.8 (runner=fixer, agent=codex)

* fix(desktop): preserve nested blend backdrops

Generated-By: looper 0.11.8 (runner=fixer, agent=codex)

* fix(desktop): honor paint order and pseudo masks

Use Chromium paint-stack hit testing for backdrop selection and preserve complete computed mask geometry on layered pseudos.

Generated-By: looper 0.11.8 (runner=fixer, agent=codex)

* fix(desktop): preserve layered PPTX compositing boundaries

Flatten nested layered backgrounds through a shared ancestor compositor, and materialize masked pseudo content and borders in the same Chromium capture while suppressing native duplicates.

Generated-By: looper 0.11.8 (runner=fixer, agent=codex)

* fix(desktop): preserve native PPTX foreground layers

Keep compositor foreground descendants editable while rasterizing only layered backgrounds, suppress captured pseudo helpers, and fully capture masked elements whose foreground cannot be serialized natively.

Generated-By: looper 0.11.8 (runner=fixer, agent=codex)

* fix(desktop): preserve PPTX backdrop and pseudo fills

Generated-By: looper 0.11.8 (runner=fixer, agent=codex)

* fix(desktop): preserve PPTX compositor root paint

Capture solid compositor-root backgrounds and ancestor backdrop effects with layered descendants, and suppress duplicate native fills for materialized pseudos.

Generated-By: looper 0.11.8 (runner=fixer, agent=codex)

* fix(desktop): capture composited pseudo foregrounds

Capture generated pseudo content and borders with layered mix-blend or backdrop-filter backgrounds so Chromium preserves their complete compositing before native pseudo suppression.

Add an Electron/PPTX pixel comparison against the authored Chromium rendering and verify no duplicate native pseudo text remains.

Generated-By: looper 0.11.8 (runner=fixer, agent=codex)

* test(desktop): normalize composited pseudo capture scale

Sample the Chromium reference at two CSS pixels regardless of host device pixel ratio so Linux/Xvfb and Retina runners compare equal-sized images.

Generated-By: looper 0.11.8 (runner=fixer, agent=codex)

* fix(desktop): preserve nested PPTX compositor paint

Capture intermediate compositor paint and real mix-blend foregrounds in Chromium while suppressing their duplicate native output.

Generated-By: looper 0.11.8 (runner=fixer, agent=codex)

* fix(desktop): preserve whole-paint PPTX captures

Generated-By: looper 0.11.8 (runner=fixer, agent=codex)

* fix(desktop): capture unsupported PPTX foreground effects

Capture text-clipped layers, unsupported ancestor-effect subtrees, and self-composited pseudos as whole Chromium paint so the editable exporter cannot emit mismatched native foregrounds.

Generated-By: looper 0.11.8 (runner=fixer, agent=codex)

* fix(desktop): preserve layered PPTX capture fidelity

Normalize Chromium capture scale by renderer DPR, capture text-clipped generated pseudos as complete paint, and retain pseudo box shadows in raster helpers.

Generated-By: looper 0.11.8 (runner=fixer, agent=codex)

* fix(desktop): preserve PPTX compositor roots

Capture slide-root effects with their layered foregrounds and use paint-aware full-overlap sampling for clipped blend backdrops.

Generated-By: looper 0.11.8 (runner=fixer, agent=codex)

* fix(desktop): bound layered PPTX paint groups

Preserve intermediate wrapper fills inside compositor captures so raster replacements keep authored paint order. Bound clipped-backdrop fallback work with stratified sampling instead of area-scaled hit testing.

Generated-By: looper 0.11.8 (runner=fixer, agent=codex)

* fix(desktop): preserve clipped PPTX blend backdrops

Replace the fixed paint-membership grid with a clip-aware Chromium paint-order probe so narrow masked or clipped backdrops cannot fall between sample centers. Cover the 1920x1080 DPR-2 case with a focused 1px stripe pixel comparison.

Generated-By: looper 0.11.8 (runner=fixer, agent=codex)

* fix(desktop): capture clipped PPTX foreground groups

Generated-By: looper 0.11.8 (runner=fixer, agent=codex)

* fix(desktop): recheck clipped PPTX backdrop order

Let clip and mask candidates reach the clip-free paint-order probe, and clear the first probe state before evaluating the second pass.

Generated-By: looper 0.11.8 (runner=fixer, agent=codex)

* test(desktop): map PPTX captures to exported media

Resolve each Chromium capture through its slide picture geometry and relationship, using pixel similarity only to disambiguate overlapping images.

Generated-By: looper 0.11.8 (runner=fixer, agent=codex)

* test(desktop): make PPTX probe scale DPR-aware

Match the Electron media probe capture scale to the production 2-physical-pixels-per-CSS-pixel formula across DPR 1 and DPR 2 renderers.

Generated-By: looper 0.11.8 (runner=fixer, agent=codex)

* fix(desktop): retain clipped PPTX backdrop order

Use full-coverage clip and mask probe values so Chromium paint-order sampling preserves the candidates' stacking contexts before authored styles are restored.\n\nGenerated-By: looper 0.11.8 (runner=fixer, agent=codex)

* fix(desktop): retain ancestor-clipped PPTX backdrops

Expand paint-order probes across standard and prefixed clip or mask ancestors, then keep the focused Chromium-to-PPTX stripe regression on that path.

Generated-By: looper 0.11.8 (runner=fixer, agent=codex)

* fix(desktop): preserve nested PPTX blend backdrops

Probe non-member compositor descendants against the actual backdrop-dependent capture members and keep selected backdrop paint visible during isolation.

Generated-By: looper 0.11.8 (runner=fixer, agent=codex)
(cherry picked from commit 12de3ed)

Co-authored-by: Ray Xi <2667192167@qq.com>

Author: open-design-release-bot[bot]