CB-WP-0035: a session that answers nothing

Two reports, one cause: the script's fetch had no .catch. When the server
had exited the promise rejected, the chain never ran, and not even the
status line moved — so a dead server and a click that did nothing were
indistinguishable. play again read as a dead button, and the linger
timeout was invisible.

Now a rejection says the session is gone and seals the page, and a
5-second heartbeat against a new /alive notices it without needing a
click, which is what the timeout case requires. The beat carries the
token, and does not extend the linger: that deadline is absolute.

The harness had the same hole. jsrun's fetch stub had no .catch, so the
branch that notices a dead server would have been unreachable in every
test — the very defect the stub's own comment records from CB-WP-0024.
Teaching it __failing, .catch and a recorded setInterval was the fix;
writing the script defensively would have repeated the trap.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

WORK-RECORDS.md

@@ -41,6 +41,7 @@
 | workplan | CB-WP-0031 | done | — | workplans/CB-WP-0031-the-comment-box-outlives-the-game.md |
 | workplan | CB-WP-0032 | done | — | workplans/CB-WP-0032-the-comments-in-the-account.md |
 | workplan | CB-WP-0033 | done | — | workplans/CB-WP-0033-a-game-is-the-unit.md |
+| workplan | CB-WP-0034 | done | — | workplans/CB-WP-0034-who-you-are-bonding-with.md |
 | task | CB-WP-0001-T01 | done | — | workplans/CB-WP-0001-inner-loop.md |
 | task | CB-WP-0001-T02 | done | — | workplans/CB-WP-0001-inner-loop.md |
 | task | CB-WP-0001-T03 | done | — | workplans/CB-WP-0001-inner-loop.md |
@@ -205,3 +206,4 @@
 | task | CB-WP-0031-T01 | done | — | workplans/CB-WP-0031-the-comment-box-outlives-the-game.md |
 | task | CB-WP-0032-T01 | done | — | workplans/CB-WP-0032-the-comments-in-the-account.md |
 | task | CB-WP-0033-T01 | done | — | workplans/CB-WP-0033-a-game-is-the-unit.md |
+| task | CB-WP-0034-T01 | done | — | workplans/CB-WP-0034-who-you-are-bonding-with.md |