test/tile-grid-sse-filter.test.ts: search for the renamed 'const eventSource = new EventSource(' end marker and require both ends, so the connect-URL check covers that block again instead of the rest of app.js
test/sse-connect-timeout.test.ts: cover the replaced-EventSource guard in _handleSseConnectionFailure() (a late error from a replaced attempt leaves the new one alone)
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
docs: document the SSE connect timeout next to the staleness watchdog in src/web/CLAUDE.md and docs/architecture-invariants.md (clear order, replaced-EventSource guards, offline handler leaves the timer)
test: rename the offline case to "connectSSE() while offline cancels the pending timer" so it names the path it drives
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
An EventSource whose request never gets response headers stays in
CONNECTING without firing open or error, so the backoff never runs and
the staleness watchdog (which only judges a 'connected' stream) cannot
see it. Bound each attempt with a 15s connect timeout: if open has not
fired, close the attempt and retry through the same path onerror uses.
The timer is cleared on open, on failure and at the top of every
connectSSE(), and both the timeout and the failure handler ignore an
EventSource that has since been replaced.
Codeman maintainer