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.

Telegram/VK stay online-only (contour review): the offline model is channel-gated via offlineCapable() (native + plain web; false in the mini-apps). offlineMode.active is hard-gated on it, so the whole model (blue chrome, unified/greyed lobby, transport kill switch, device-local vs_ai/hotseat create) stays inert in Telegram/VK regardless of the detected net state (closing a version-lock path that could have flipped them offline); and New Game's with-friends hides the online/offline segment there, leaving the remote invite alone. ARCHITECTURE already declared "Telegram/VK are exempt" - this makes the code match.

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; two new telegram.spec.ts e2e (offline signal keeps the chrome online + quick-match opponent choice visible => server enqueue; with-friends shows no pass-and-play), RED-verified; svelte-check 0/0, vitest 617, e2e 248 (chromium + webkit), build + bundle-size 127.8/130.

gateway/internal/config/config.go

@@ -60,6 +60,11 @@ type Config struct {
 	// "update required" signal before its payload is decoded. Empty leaves the gate dormant
 	// (every client is served) — the default for web-only deployments.
 	MinClientVersion string
+	// RecommendedClientVersion, when non-empty, is the version below which a served client is nudged
+	// to update — a non-blocking "update available" signal (the X-Update-Recommended response header)
+	// on gated responses; the call still succeeds. It must be at least MinClientVersion. Empty leaves
+	// the soft tier off (the default); it does not affect the hard MinClientVersion gate.
+	RecommendedClientVersion string
 	// RateLimit configures the in-memory anti-abuse limiter.
 	RateLimit RateLimitConfig
 	// Abuse configures the temporary IP ban and the honeytoken (prod-only).
@@ -232,15 +237,16 @@ func (c VKIDConfig) Enabled() bool {
 func Load() (Config, error) {
 	var err error
 	c := Config{
-		HTTPAddr:         envOr("GATEWAY_HTTP_ADDR", defaultHTTPAddr),
-		LogLevel:         envOr("GATEWAY_LOG_LEVEL", defaultLogLevel),
-		BackendHTTPURL:   envOr("GATEWAY_BACKEND_HTTP_URL", defaultBackendHTTPURL),
-		BackendGRPCAddr:  envOr("GATEWAY_BACKEND_GRPC_ADDR", defaultBackendGRPCAddr),
-		AdminUser:        os.Getenv("GATEWAY_ADMIN_USER"),
-		AdminPassword:    os.Getenv("GATEWAY_ADMIN_PASSWORD"),
-		ValidatorAddr:    os.Getenv("GATEWAY_VALIDATOR_ADDR"),
-		VKAppSecret:      os.Getenv("GATEWAY_VK_APP_SECRET"),
-		MinClientVersion: os.Getenv("GATEWAY_MIN_CLIENT_VERSION"),
+		HTTPAddr:                 envOr("GATEWAY_HTTP_ADDR", defaultHTTPAddr),
+		LogLevel:                 envOr("GATEWAY_LOG_LEVEL", defaultLogLevel),
+		BackendHTTPURL:           envOr("GATEWAY_BACKEND_HTTP_URL", defaultBackendHTTPURL),
+		BackendGRPCAddr:          envOr("GATEWAY_BACKEND_GRPC_ADDR", defaultBackendGRPCAddr),
+		AdminUser:                os.Getenv("GATEWAY_ADMIN_USER"),
+		AdminPassword:            os.Getenv("GATEWAY_ADMIN_PASSWORD"),
+		ValidatorAddr:            os.Getenv("GATEWAY_VALIDATOR_ADDR"),
+		VKAppSecret:              os.Getenv("GATEWAY_VK_APP_SECRET"),
+		MinClientVersion:         os.Getenv("GATEWAY_MIN_CLIENT_VERSION"),
+		RecommendedClientVersion: os.Getenv("GATEWAY_RECOMMENDED_CLIENT_VERSION"),
 		VKID: VKIDConfig{
 			AppID:        os.Getenv("GATEWAY_VK_ID_APP_ID"),
 			ClientSecret: os.Getenv("GATEWAY_VK_ID_CLIENT_SECRET"),
@@ -344,6 +350,18 @@ func (c Config) validate() error {
 			return fmt.Errorf("config: GATEWAY_MIN_CLIENT_VERSION %q is not a MAJOR.MINOR.PATCH version", c.MinClientVersion)
 		}
 	}
+	if c.RecommendedClientVersion != "" {
+		rec, ok := clientver.Parse(c.RecommendedClientVersion)
+		if !ok {
+			return fmt.Errorf("config: GATEWAY_RECOMMENDED_CLIENT_VERSION %q is not a MAJOR.MINOR.PATCH version", c.RecommendedClientVersion)
+		}
+		// The soft tier must sit at or above the hard minimum: a recommended below the minimum is a
+		// misconfiguration (every client below min is already turned away). An empty/unparseable
+		// minimum imposes no lower bound, so the recommended may stand alone.
+		if min, ok := clientver.Parse(c.MinClientVersion); ok && clientver.Less(rec, min) {
+			return fmt.Errorf("config: GATEWAY_RECOMMENDED_CLIENT_VERSION %q must be >= GATEWAY_MIN_CLIENT_VERSION %q", c.RecommendedClientVersion, c.MinClientVersion)
+		}
+	}
 	if c.Abuse.BanEnabled && (c.Abuse.BanThreshold <= 0 || c.Abuse.BanWindow <= 0 || c.Abuse.BanDuration <= 0) {
 		return fmt.Errorf("config: GATEWAY_ABUSE_BAN_THRESHOLD/_WINDOW/_DURATION must be positive when GATEWAY_ABUSE_BAN_ENABLED")
 	}