feat(offline): implicit net-state model, two-tier version gate, unified lobby

Land the offline-model redesign (ANDROID_PLAN.md O1-O7): replace the explicit offline toggle with a single detected net-state machine, unify the lobby, and add a two-tier client-version gate. Contour-safe: both version vars empty => dormant, the wire change is additive, so web/pwa/vk/tg behaviour is unchanged unless the gate is deliberately configured.

O1 net-state reducer (test-first). O2 store + wiring (connection/offline shims; +@capacitor/network). O3 remove the offline toggle + migrate the pref. O4 two-tier gate: hard update_required degrades to an offline Update/Play-offline notice (not terminal); soft GATEWAY_RECOMMENDED_CLIENT_VERSION -> X-Update-Recommended nudge. O5 unified lobby (device-local + greyed-from-cache server games; self-set identity; closes G-step-0). O6 create flows (with-friends online/offline segment + offline dict guard). O7 docs.

Deploy/CI: wire the version gate through the deploy (GATEWAY_MIN_CLIENT_VERSION + GATEWAY_RECOMMENDED_CLIENT_VERSION as plain unprefixed vars via compose + ci.yaml + prod-deploy.yaml + write-prod-env.sh + .env.example) so the gate is live when set (test-contour commit-hash version fails open; empty => dormant). Disable the manual android-build CI workflow for now (rename .disabled). Bump the app bundle budget 127->130 KB for the added always-loaded wiring. Fix the UI Docker stage (gateway/Dockerfile): install --ignore-scripts so the Alpine/musl SPA build no longer tries to native-build sharp (a local android:assets tool, unused in the image); esbuild's binary is an optional dep so Vite still builds.

Tests: gateway go green (two-tier gate over a real HTTP handler); docker build of the landing + gateway targets green locally; compose --no-interpolate confirms the gateway env; svelte-check 0/0, vitest 617, e2e 122/122 (chromium + webkit).

deploy/docker-compose.yml

@@ -222,6 +222,12 @@ services:
       GATEWAY_HTTP_ADDR: ":8081"
       GATEWAY_BACKEND_HTTP_URL: http://backend:8080
       GATEWAY_BACKEND_GRPC_ADDR: backend:9090
+      # Client-version gate (ARCHITECTURE.md §2): the hard minimum + the soft recommended client build.
+      # Empty ⇒ dormant. Plain (unprefixed) — the same value serves every contour; in the test contour
+      # the stamped client version is a commit hash (unparseable ⇒ fail-open), so the gate only bites
+      # real semver builds in prod. Validated at gateway start (recommended must be ≥ min).
+      GATEWAY_MIN_CLIENT_VERSION: ${GATEWAY_MIN_CLIENT_VERSION:-}
+      GATEWAY_RECOMMENDED_CLIENT_VERSION: ${GATEWAY_RECOMMENDED_CLIENT_VERSION:-}
       # Telegram auth validates against the home validator (plaintext, internal).
       GATEWAY_VALIDATOR_ADDR: validator:9091
       # VK Mini App auth verifies the launch-parameter signature in-process under the VK