Embedded area readiness during export

An exported document must wait for an embedded view's first control before treating that view as settled. The remote layout stream initially emits null while its control slot is absent. A quiet null frame establishes no rendered content; exporting it produced the visible unavailable notice even when the owner was still preparing a valid view.

AreaMarkupRenderer.Settle now skips only leading nulls. After a real control arrives, its existing quiet-window rule still chooses the snapshot, and a later null still withdraws content rather than exporting a stale control. An empty completed stream emits one null result. The existing overall deadline remains in place for a view that never becomes available. No permission scope, rendering identity, error handling, timeout setting or source subscription route changes.

Evidence

Plugins main run 34567556709, Export job 103164485805, failed DocumentExportLayoutAreaTest.DocxExport_RendersEmbeddedLayoutArea_AsRealWordContent on 2026-09-11. The DOCX contained an unavailable OgCard notice instead of QUANTUMLEDGER; 200 of 201 suite cases passed. The run used Plugins dab97cb304792222de262bd3fcb96439796ed8b0; its resolver selected source/script ref 6231c4da4c1baa5dbcc9e44b43020006583fcb2c, while the resolved 8322 tester and image target used framework checkout 6e02488. The local reproduction and validation below built framework 6231c4da4c1baa5dbcc9e44b43020006583fcb2c in isolation. The renderer and failed test were byte-identical to the prior Plugins d6fa0338 publication.

The focused regression uses the real layout owner and its remote synchronization stream. It first observes the actual null control, keeps the owner unresolved beyond the default 750 ms quiet window, and then releases a control containing QUANTUMLEDGER. On the unchanged baseline it failed the negative assertion: empty markup was emitted within one second, before any real control had been produced. This directly proves the premature-settlement path. The CI artifact has no control-frame trace, so it does not establish the exact timing of the original CI owner's first emission; that attribution remains consistent with the symptom rather than observed.

The additional controls cover empty completion, null-only completion, no emission, a pending null, and withdrawal of a previously available control. They require exactly one unavailable result within the existing bounded behavior. End-to-end export and access tests retain both the allowed embedded-content positive control and the denied-content negative control.

The amended focused selection passed 11/11. The full Export suite ran once with DOTNET_PROCESSOR_COUNT=4 and passed 207/207 in 67.910 seconds, with zero errors, skips or unrun tests. Both baseline and amended projects built in Release with warnings as errors and reported zero warnings/errors. These are executed local results, not a claim that the amended publication has reached production.

Original CI evidence and local before/after TRXs are retained under /private/tmp/roadmap-export-readiness-evidence. The committed tests do not depend on this local path. No production or preview mutation is part of this investigation.

Current-main integration on 2026-09-11

The prepared merge of the common workflow fixture repair d07ee196 was rebuilt strictly and executed 207/207 Export cases in 90.720 seconds, with zero errors, failures, skips or unrun cases. This is a second receipt, separate from the earlier 67.910-second run. Its raw log and TRX are /tmp/sav-export-fixture-integration-full.log and /tmp/sav-export-fixture-integration-full.trx; the build reported zero warnings and errors.

Main 05fde510 then brought FleetWatch and the independently landed GitSync fixture correction (#1649). The overlapping fixture payloads retain main's parameterized workflow-path checks and the three separate refusal-then-corrected-path controls from #1650. These two resolved test files are byte-identical to the combined source validated in roadmap integration 6d31e238: strict build and 199/199 GitSync cases against core 818c10649389c158594dc20c3e7792367f2cb51f. Export product and test sources remain byte-identical to 1c54785c; this integration changes no renderer behavior or test assertion. The GitSync fixture failure is already repaired on main; this PR's remaining product repair is embedded-area readiness. The local receipts do not establish production adoption or a passing new CI run.