feat: introduce notification system and claude notifications (#450)

* feat: introduce notification system and claude notifications

* fix(sw): prevent caching of API requests and WebSocket upgrades

* default to false for webpush notifications and translations for the button

* fix: notifications orchestrator and add a notification when  first enabled

* fix: remove unused state update and dependency in settings controller hook

* fix: show notifications settings tab

* fix: add notifications for response completion for all providers

* feat: show session name in notification and don't reload tab on clicking
--- the notification

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
Co-authored-by: Haileyesus <something@gmail.com>

src/hooks/useWebPush.ts

@@ -0,0 +1,103 @@
+import { useCallback, useEffect, useState } from 'react';
+import { authenticatedFetch } from '../utils/api';
+
+type WebPushState = {
+  permission: NotificationPermission | 'unsupported';
+  isSubscribed: boolean;
+  isLoading: boolean;
+  subscribe: () => Promise<void>;
+  unsubscribe: () => Promise<void>;
+};
+
+function urlBase64ToUint8Array(base64String: string): Uint8Array {
+  const padding = '='.repeat((4 - (base64String.length % 4)) % 4);
+  const base64 = (base64String + padding).replace(/-/g, '+').replace(/_/g, '/');
+  const rawData = window.atob(base64);
+  const outputArray = new Uint8Array(rawData.length);
+  for (let i = 0; i < rawData.length; ++i) {
+    outputArray[i] = rawData.charCodeAt(i);
+  }
+  return outputArray;
+}
+
+export function useWebPush(): WebPushState {
+  const [permission, setPermission] = useState<NotificationPermission | 'unsupported'>(() => {
+    if (typeof window === 'undefined' || !('Notification' in window) || !('serviceWorker' in navigator)) {
+      return 'unsupported';
+    }
+    return Notification.permission;
+  });
+  const [isSubscribed, setIsSubscribed] = useState(false);
+  const [isLoading, setIsLoading] = useState(false);
+
+  // Check existing subscription on mount
+  useEffect(() => {
+    if (permission === 'unsupported') return;
+
+    navigator.serviceWorker.ready.then((registration) => {
+      registration.pushManager.getSubscription().then((sub) => {
+        setIsSubscribed(sub !== null);
+      });
+    }).catch(() => {
+      // SW not ready yet
+    });
+  }, [permission]);
+
+  const subscribe = useCallback(async () => {
+    if (permission === 'unsupported') return;
+    setIsLoading(true);
+
+    try {
+      const perm = await Notification.requestPermission();
+      setPermission(perm);
+      if (perm !== 'granted') return;
+
+      const keyRes = await authenticatedFetch('/api/settings/push/vapid-public-key');
+      const { publicKey } = await keyRes.json();
+
+      const registration = await navigator.serviceWorker.ready;
+      const subscription = await registration.pushManager.subscribe({
+        userVisibleOnly: true,
+        applicationServerKey: urlBase64ToUint8Array(publicKey).buffer as ArrayBuffer,
+      });
+
+      const subJson = subscription.toJSON();
+      await authenticatedFetch('/api/settings/push/subscribe', {
+        method: 'POST',
+        body: JSON.stringify({
+          endpoint: subJson.endpoint,
+          keys: subJson.keys,
+        }),
+      });
+
+      setIsSubscribed(true);
+    } catch (err) {
+      console.error('Push subscribe failed:', err);
+    } finally {
+      setIsLoading(false);
+    }
+  }, [permission]);
+
+  const unsubscribe = useCallback(async () => {
+    setIsLoading(true);
+    try {
+      const registration = await navigator.serviceWorker.ready;
+      const subscription = await registration.pushManager.getSubscription();
+      if (subscription) {
+        const endpoint = subscription.endpoint;
+        await subscription.unsubscribe();
+        await authenticatedFetch('/api/settings/push/unsubscribe', {
+          method: 'POST',
+          body: JSON.stringify({ endpoint }),
+        });
+      }
+      setIsSubscribed(false);
+    } catch (err) {
+      console.error('Push unsubscribe failed:', err);
+    } finally {
+      setIsLoading(false);
+    }
+  }, []);
+
+  return { permission, isSubscribed, isLoading, subscribe, unsubscribe };
+}