feat(web): wire feature-flag and kill-switch platform clients

- Added @bytelyst/feature-flag-client and @bytelyst/kill-switch-client deps
- Created web/src/lib/feature-flags.ts — poll-based flag client (fail-open)
- Created web/src/lib/kill-switch.ts — kill-switch check client (fail-open)
- Telemetry, diagnostics, extraction were already wired

Verification: web typecheck + 6 tests pass.

web/package-lock.json

@@ -1,17 +1,19 @@
 {
-  "name": "bytelyst-agentic-notes-web",
+  "name": "@notelett/web",
   "version": "0.1.0",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
-      "name": "bytelyst-agentic-notes-web",
+      "name": "@notelett/web",
       "version": "0.1.0",
       "dependencies": {
         "@bytelyst/api-client": "file:../../learning_ai_common_plat/packages/api-client",
         "@bytelyst/auth-client": "file:../../learning_ai_common_plat/packages/auth-client",
         "@bytelyst/design-tokens": "file:../../learning_ai_common_plat/packages/design-tokens",
         "@bytelyst/diagnostics-client": "file:../../learning_ai_common_plat/packages/diagnostics-client",
+        "@bytelyst/feature-flag-client": "file:../../learning_ai_common_plat/packages/feature-flag-client",
+        "@bytelyst/kill-switch-client": "file:../../learning_ai_common_plat/packages/kill-switch-client",
         "@bytelyst/platform-client": "file:../../learning_ai_common_plat/packages/platform-client",
         "@bytelyst/react-auth": "file:../../learning_ai_common_plat/packages/react-auth",
         "@bytelyst/telemetry-client": "file:../../learning_ai_common_plat/packages/telemetry-client",
@@ -67,6 +69,14 @@
         "zod": "^3.22.0"
       }
     },
+    "../../learning_ai_common_plat/packages/feature-flag-client": {
+      "name": "@bytelyst/feature-flag-client",
+      "version": "0.1.0"
+    },
+    "../../learning_ai_common_plat/packages/kill-switch-client": {
+      "name": "@bytelyst/kill-switch-client",
+      "version": "0.1.0"
+    },
     "../../learning_ai_common_plat/packages/platform-client": {
       "name": "@bytelyst/platform-client",
       "version": "0.1.0"
@@ -458,6 +468,14 @@
       "resolved": "../../learning_ai_common_plat/packages/diagnostics-client",
       "link": true
     },
+    "node_modules/@bytelyst/feature-flag-client": {
+      "resolved": "../../learning_ai_common_plat/packages/feature-flag-client",
+      "link": true
+    },
+    "node_modules/@bytelyst/kill-switch-client": {
+      "resolved": "../../learning_ai_common_plat/packages/kill-switch-client",
+      "link": true
+    },
     "node_modules/@bytelyst/platform-client": {
       "resolved": "../../learning_ai_common_plat/packages/platform-client",
       "link": true
@@ -4801,6 +4819,7 @@
       "integrity": "sha512-whOE1HFo/qJDyX4SnXzP4N6zOWn79WhnCUY/iDR0mPfQZO8wcYE4JClzI2oZrhBnnMUCBCHZhO6VQyoBU95mZA==",
       "dev": true,
       "license": "MIT",
+      "peer": true,
       "dependencies": {
         "@rtsao/scc": "^1.1.0",
         "array-includes": "^3.1.9",
@@ -8454,6 +8473,7 @@
       "integrity": "sha512-w+N7Hifpc3gRjZ63vYBXA56dvvRlNWRczTdmCBBa+CotUzAPf5b7YMdMR/8CQoeYE5LX3W4wj6RYTgonm1b9DA==",
       "dev": true,
       "license": "MIT",
+      "peer": true,
       "dependencies": {
         "esbuild": "^0.27.0",
         "fdir": "^6.5.0",

web/package.json

@@ -16,6 +16,8 @@
     "@bytelyst/auth-client": "file:../../learning_ai_common_plat/packages/auth-client",
     "@bytelyst/design-tokens": "file:../../learning_ai_common_plat/packages/design-tokens",
     "@bytelyst/diagnostics-client": "file:../../learning_ai_common_plat/packages/diagnostics-client",
+    "@bytelyst/feature-flag-client": "file:../../learning_ai_common_plat/packages/feature-flag-client",
+    "@bytelyst/kill-switch-client": "file:../../learning_ai_common_plat/packages/kill-switch-client",
     "@bytelyst/platform-client": "file:../../learning_ai_common_plat/packages/platform-client",
     "@bytelyst/react-auth": "file:../../learning_ai_common_plat/packages/react-auth",
     "@bytelyst/telemetry-client": "file:../../learning_ai_common_plat/packages/telemetry-client",

web/src/lib/feature-flags.ts

@@ -0,0 +1,28 @@
+"use client";
+
+import { createFeatureFlagClient } from "@bytelyst/feature-flag-client";
+import { PLATFORM_SERVICE_URL, PRODUCT_ID } from "@/lib/product-config";
+
+let initialized = false;
+
+const featureFlagClient = createFeatureFlagClient({
+  baseUrl: PLATFORM_SERVICE_URL,
+  productId: PRODUCT_ID,
+  platform: "web",
+  pollIntervalMs: 5 * 60 * 1000,
+});
+
+export async function initFeatureFlags(userId?: string) {
+  if (initialized) return featureFlagClient;
+  await featureFlagClient.init({ userId }).catch(() => {
+    // Feature flags are best-effort — fail-open
+  });
+  initialized = true;
+  return featureFlagClient;
+}
+
+export function isFeatureEnabled(key: string): boolean {
+  return featureFlagClient.isEnabled(key);
+}
+
+export { featureFlagClient };

web/src/lib/kill-switch.ts

@@ -0,0 +1,16 @@
+"use client";
+
+import { createKillSwitchClient } from "@bytelyst/kill-switch-client";
+import { PLATFORM_SERVICE_URL, PRODUCT_ID } from "@/lib/product-config";
+
+const killSwitchClient = createKillSwitchClient({
+  baseUrl: PLATFORM_SERVICE_URL,
+  productId: PRODUCT_ID,
+  platform: "web",
+});
+
+export async function checkKillSwitch(): Promise<{ disabled: boolean; message: string | null }> {
+  return killSwitchClient.check();
+}
+
+export { killSwitchClient };