Introduce a minimum-supported-client gate so a future incompatible wire change
can turn away installed builds too old to speak it, cleanly, instead of letting
them crash on decode. It rides the outermost stable layer (an HTTP header), never
the FlatBuffers payload.
Gateway:
- New internal/clientver: dependency-free parse + compare of the leading
MAJOR.MINOR.PATCH (a git-describe suffix is tolerated).
- GATEWAY_MIN_CLIENT_VERSION config (empty => gate dormant; validated at load).
- connectsrv checks the X-Client-Version header before decoding the payload:
Execute returns result_code="update_required" (before the registry lookup),
Subscribe returns FailedPrecondition. It fails open on an absent or garbled
header — the header is a client-controlled compatibility signal, not an access
control.
Client:
- Attach X-Client-Version on every call.
- A terminal update.svelte.ts store + a non-dismissable UpdateOverlay (native
opens VITE_STORE_URL, web reloads); retry.ts maps FailedPrecondition to the
update_required sentinel; a mock __update hook drives the e2e.
Wire-additive and contour-safe: no FBS/proto regen, no schema migration; the gate
stays dormant until GATEWAY_MIN_CLIENT_VERSION is deliberately set, so web / VK /
Telegram behaviour is unchanged. The silent reconciliation seam is deferred to the
offline-first work (its only caller). Tests: Go clientver/config/connectsrv gate
tests, retry.test.ts, Playwright update.spec.ts.
A dropped/reset/timed-out connection can surface as a Connect code other than
Unavailable (Canceled/DeadlineExceeded/Unknown/…) which fell through to the generic
'internal' -> a red 'something went wrong' toast appeared alongside the Connecting
spinner. Now toGatewayError (moved to the pure retry.ts, unit-tested) collapses every
transport-level code to 'unavailable' so it is retried + flips offline; and handleError
suppresses the toast for any connection code AND whenever the app is mid-reconnect
(!connection.online), covering the race where a unary error lands before the stream
reports the drop. Genuine server-internal / domain errors still toast while online.
Connectivity failures become state, not a toast on every attempt. A global online
signal (lib/connection.svelte.ts) flips on a transport unavailable / rate_limited and
on the live stream's drop, driving a pure-CSS header spinner + 'Connecting…' in place
of the title and softly disabling the in-game server actions (commit / exchange / pass
/ hint; local board/rack/reset stay live).
- transport: exec auto-retries with capped exponential backoff — every op on a
rate-limit (rejected before processing, safe), reads only on unavailable (a mutation
is never blindly re-sent, to avoid double-applying one whose response was lost; its
button is disabled while offline so the player re-issues on reconnect). A reachability
watcher (profile.get probe) and any successful traffic clear the signal.
- the old red error.unavailable toast is gone (handleError suppresses connection codes;
the indicator replaces it). A server-data screen still opens with the spinner and
fills on reconnect (global indicator + read auto-retry), so navigation is never dead.
- pure retry policy unit-tested (retry.ts); a mock-only window.__conn hook drives a
Chromium+WebKit e2e (indicator shows offline, the action disables, both clear on
reconnect). Full suite + build green.
- docs: ARCHITECTURE transport note, FUNCTIONAL (+ _ru), PLAN tracker (incl. #1 — the
bot already drains all updates, no change).
Also records #1 as investigated/no-change in PLAN. Other server-action buttons (chat
send, profile save, …) still degrade to a safe no-op offline; visual disable is easy to
extend.
Ilia Denisov