Three findings, all valid.
**The read/get stages asserted an RPC status, not a render.** #2148 asks
for the resource content and the prompt messages to *render*, and
`data-read-status` / `data-get-status` flip the moment the call resolves
— so the smoke stayed green with the panel deleted. `ResourcePreviewPanel`
and `PromptMessagesDisplay` now carry `data-testid="resource-preview"` /
`"prompt-messages"`, and each stage waits on the status **and** the
rendered panel. Verified by breaking each testid: the smoke fails with
`reading `events` did not render a preview — last observed:
data-read-status="ok"`, which is the finding stated back exactly.
**`smoke:web:tabs` followed ambient `SMOKE_BROWSER`**, so
`SMOKE_BROWSER=firefox npm run ci` would have run the supposedly
Chromium-only smoke under Firefox — contradicting both this PR's stated
scope and the gated-tier invariant in `run-engine-smokes.test.mjs`. The
npm script now pins `chromium` on **both** halves (install and launch)
and the smoke resolves through `resolveRequestedBrowser(argv, env)`, where
an explicit argument wins over the environment; a new case in that same
test file pins it, including that the smoke stays out of `ENGINE_SMOKES`.
**The AGENTS rules were not mirrored into `.github/copilot-instructions.md`.**
Correct, and worse than an omission: that file's engine bullet asserts the
headless web smokes are "engine-parameterized, not Chromium-only", which
this PR made false. It now names `smoke:web:tabs` as the deliberate
exception, and carries the genuinely review-citable new rule — assert
`data-*`, never copy, and never stop at an RPC status where the ask was
that something render.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UL9retfvAXRgvi6EWk4SY4
Signed-off-by: cliffhall <cliff@futurescale.com>
23088e9c69