Make preview observations deterministic

Owner: OS runtime and mobile maintainers. Revisit by 2026-09-22.

PR #2599 does not change mobile chat/notes or facet lifecycle code. Its preview runs exposed these unrelated test problems while validating document review.

Facet source-version observation#

apps/os/e2e/vitest/userspace-facet-source-version.e2e.test.ts cannot distinguish commit-triggered rebuilds from unrelated recycling, even across three rounds. The underlying limitation is already tracked in tasks/platform-stall-repros.md (thread 5), with a companion forced-recycle reproduction.

Evidence from Depot org 0p91s0lz49:

• Run 9184gpn9n2, attempt kk45h33gvr, head 0271e5812: the body passed in 92.6s, making the strict SAME-BOOT STALENESS pin unexpectedly red.
• Its unchanged-commit rerun, attempt 7wllws629m, passed the integration suite with the expected staleness observation.
• Run jbjdctf2ck, attempt lf340f6k0c, head c2e2fff65: the body passed in 75.4s, again making the strict pin red. All 58 other integration files passed.

The test now uses createFlake for exactly /SAME-BOOT STALENESS/: both success and this known failure remain measured on every run. Different errors and hangs stay red. The body and its 230s watchdog are unchanged; no test is skipped. This does not declare the runtime bug fixed.

Exit criteria: record rebuild provenance so this observation can distinguish an actual source-triggered replacement from recycling; then restore a strict pin if the defect persists, or an ordinary passing test once fixed. Inspect the measured outcomes before changing the wrapper.

Mobile note-to-chat navigation#

specs/mobile/notes.spec.ts failed at inputValue() after “Chat about this note” in both attempts of 9184gpn9n2 and jbjdctf2ck. The captured page already shows the correct prefilled Message textbox. inputValue() bypasses the navigation and spinner middleware used by waitFor().

The spec now waits for the textbox through that middleware before reading its value. No action timeout was increased and no flake wrapper was added. The live preview must validate the complete capture/edit/chat/send/delete flow.