Isolated experiment owned by Codex-956atf /root/requirements_delta. The complete initial example is alarm-response.arcadia; probe.rs calls the existing public core. No proposed new syntax is implemented here.

The final run passed with no model warnings on 2026-09-11. See probe-output.txt and the parent design report. Generated source alternatives live in observed/: open stabilized.arcadia, canonical.arcadia, renamed.arcadia or reparented.arcadia individually. The split example consists of split-entry.arcadia plus participants.arcadia. The six alternatives are not one SourceBundle.

The split-entry snapshot retains the indentation on the blank line left by moving its participant declaration. That trailing whitespace is intentional observed source, not a hand-authored formatting requirement; preserve the snapshot's bytes when using it as evidence.

The reader lease used Rust 1.98.1 gnullvm and core artifact liboa_core-6c8da57367eec642.rlib, SHA-256 D7EFB5F3C423FF8AF13637F53CC481502C7F317BF01E9D072F9EFD64CD954C13. Root retains Cargo/build ownership. The temporary probe executable was removed; no target artifact was changed.

From the repository root, after the build owner identifies the matching artifact and grants a reader lease:

. .local\toolchain\env.ps1
$authoringCore = (Get-Item -LiteralPath 'target\debug\deps\liboa_core-6c8da57367eec642.rlib').FullName
$authoringDeps = Join-Path (Get-Location) 'target\debug\deps'
$authoringProbe = Join-Path (Get-Location) 'harness\experiments\textual-authoring-20260911\probe.exe'
rustc --edition=2024 'harness\experiments\textual-authoring-20260911\probe.rs' --extern "oa_core=$authoringCore" -L "dependency=$authoringDeps" -C linker=clang.exe -o $authoringProbe
if ($LASTEXITCODE -ne 0) { throw 'Probe compilation failed' }
& $authoringProbe 'harness\experiments\textual-authoring-20260911\alarm-response.arcadia' 'harness\experiments\textual-authoring-20260911\observed-rerun'
if ($LASTEXITCODE -ne 0) { throw 'Probe assertions failed' }

Each run intentionally authors a new model from omitted IDs, so regenerated UUID bytes differ across runs. Assertions test stable identity only after adopting that run's accepted bundle. The retained observed/ snapshots are the exact final run, not deterministic UUID fixtures. The probe does not test HTTP/native UI, save recovery, performance or a new grammar.