Close the fixed blocker, and record what withdrawal converging faster does NOT mean

Six variations against the real application, one thing varied at a time: the
sign-up-breaks-the-next-connection defect is gone. New identity, immediate
reload or delayed; an identity already used for several cycles; and the very
identity poisoned by the pre-fix code, which now reconnects cleanly three times
out of three. So nothing needed healing -- the fix does not merely stop writing
the bad state, it makes what was already written harmless. The leaf is deleted
rather than graduated: its reproduction method, the stale-server trap it led to,
and "a provider gap is not worked around here" all live elsewhere already.

The count defect stays open, with its shape now known: it does converge across
connections, but takes one more than expected -- the first reconnect still shows
zero, the second shows the value.

And a correction worth keeping. The explanation offered for why withdrawal
converges in a single connection -- that it writes straight to the owner's
document instead of depositing -- is contradicted by the code: it deposits its
own marker into the same inbox, drained by the same owner routine, "symmetric"
by the code's own comment. The asymmetry is real and recorded as verified; its
cause is recorded as unknown rather than filled with a plausible story. Same
mechanism, same inbox, two connections against one, is a lead worth having
honestly.

The dev-server caveat is upgraded from inferred to verified, and it is worse
than it read: an edit to application source triggers a genuine rebuild, new
bundle hash and all, and that rebuild still carries the stale dependency. Only a
restart works, and "touch a file to force a rebuild" is now explicitly ruled out
as a substitute.

.project/concepts/bdd-testing/cookbook_live-probe.md

@@ -10,7 +10,7 @@ A **probe** is a one-off Playwright script, outside Cucumber — no World, no ho
 
 ## When to reach for one
 
-Before believing a flow works. The create-and-participate flow had been declared *correct by construction* on typecheck, build and reading; the first probe ever run against it found **three defects** none of those could see — two still open ([[bug_signup-breaks-the-next-connection]], [[bug_participant-count-stays-at-zero]] in `data-layer`) and one shipped as a fix.
+Before believing a flow works. The create-and-participate flow had been declared *correct by construction* on typecheck, build and reading; the first probe ever run against it found **three defects** none of those could see — one still open ([[bug_participant-count-stays-at-zero]] in `data-layer`) and two shipped as fixes.
 
 Reach for it when the suite cannot answer the question: the `@data` run dies silently from around its sixth scenario ([[caveat_wallet-bloat-hang]]), its scenarios have no fixtures ([[caveat_data-suite-has-no-fixtures]]), and entry paths are covered by nothing ([[caveat_first-time-entry-untested]], `app-architecture` → [[caveat_boot-unverified-outside-broker]]).