Copilot review round 4 on #2100. All three findings are the same error:
clients/web/README.md documents the limitation correctly, and every
port-forwarding blurb then said the opposite.
An unpublished/unforwarded port is NOT the opaque-origin fallback case. The
backend's listener binds fine inside the container, so publication succeeds
and the browser is handed a URL it cannot reach — the frame stays blank,
with no console warning, because a cross-origin navigation failure is not
observable from the page. The fallback and its warning cover the failures
the BACKEND can see: no listener, a port that never bound, an older backend,
a network error.
Corrected in the root README's Docker blurb and the migration guide's
third-port recipe. The migration guide's troubleshooting entry had the wrong
symptom for the same reason — a missing forward produces a blank frame, not
an app whose requests are rejected — so it now leads with that and keeps the
rejected-requests case beside it as the neighbouring symptom, since the two
have opposite causes and opposite console output.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0177mPHAdECD18nLLCTwR5rh
Signed-off-by: cliffhall <cliff@futurescale.com>