Add notifications feature and update feature flags

This update includes creating new files for the notifications feature along with adding two feature flags for enabling notifications and realtime notifications. All the code and package dependencies required for the notifications functionality have been added. The 'pnpm-lock.yaml' has also been updated due to the inclusion of new package dependencies.

packages/features/notifications/src/hooks/index.ts

@@ -0,0 +1,2 @@
+export * from './use-fetch-notifications';
+export * from './use-dismiss-notification';

packages/features/notifications/src/hooks/use-dismiss-notification.ts

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+import { useCallback } from 'react';
+
+import { useSupabase } from '@kit/supabase/hooks/use-supabase';
+
+export function useDismissNotification() {
+  const client = useSupabase();
+
+  return useCallback(
+    async (notification: number) => {
+      const { error } = await client
+        .from('notifications')
+        .update({ dismissed: true })
+        .eq('id', notification);
+
+      if (error) {
+        throw error;
+      }
+    },
+    [client],
+  );
+}

packages/features/notifications/src/hooks/use-fetch-notifications.ts

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+import { useEffect, useRef } from 'react';
+
+import { useSupabase } from '@kit/supabase/hooks/use-supabase';
+
+type Notification = {
+  id: number;
+  body: string;
+  dismissed: boolean;
+  type: 'info' | 'warning' | 'error';
+  created_at: string;
+  link: string | null;
+  entity_id: string | null;
+  entity_type: string | null;
+};
+
+export function useFetchNotifications({
+  onNotifications,
+  accountIds,
+  realtime,
+}: {
+  onNotifications: (notifications: Notification[]) => unknown;
+  accountIds: string[];
+  realtime: boolean;
+}) {
+  const client = useSupabase();
+  const didFetchInitialData = useRef(false);
+
+  useEffect(() => {
+    let realtimeSubscription: { unsubscribe: () => void } | null = null;
+
+    if (realtime) {
+      const channel = client.channel('notifications-channel');
+
+      realtimeSubscription = channel
+        .on(
+          'postgres_changes',
+          {
+            event: 'INSERT',
+            schema: 'public',
+            filter: `account_id=in.(${accountIds.join(', ')})`,
+            table: 'notifications',
+          },
+          (payload) => {
+            onNotifications([payload.new as Notification]);
+          },
+        )
+        .subscribe();
+    }
+
+    if (!didFetchInitialData.current) {
+      const now = new Date().toISOString();
+
+      const initialFetch = client
+        .from('notifications')
+        .select(
+          `id, 
+           body, 
+           dismissed, 
+           type, 
+           created_at, 
+           link, 
+           entity_id, 
+           entity_type
+           `,
+        )
+        .in('account_id', accountIds)
+        .eq('dismissed', false)
+        .gt('expires_at', now)
+        .order('created_at', { ascending: false })
+        .limit(10);
+
+      didFetchInitialData.current = true;
+
+      void initialFetch.then(({ data, error }) => {
+        if (error) {
+          throw error;
+        }
+
+        if (data) {
+          onNotifications(data);
+        }
+      });
+    }
+
+    return () => {
+      if (realtimeSubscription) {
+        realtimeSubscription.unsubscribe();
+      }
+    };
+  }, [client, onNotifications, accountIds, realtime]);
+}