Document the default Zoom OAuth provider

The Zoom auth provider page said Arcade does not offer a default Zoom
provider, but a default Arcade-managed Zoom provider now exists and is
selected when a project has no custom Zoom provider. Restructure the page
to match the Google auth provider page: default provider with supported
scopes and limitations, then the custom provider flow for production.

Also expand the Zoom app redirect instructions: the Arcade redirect URL
must be present in both the Redirect URL for OAuth field and the OAuth
Allow List, otherwise Zoom rejects authorization with an Invalid redirect
error (4,700).

Claude-Session: https://claude.ai/code/session_01N2Yif5hJmtiyQoY1XR39ew

Author: iherdt

app/en/references/auth-providers/zoom/page.mdx

@@ -2,12 +2,6 @@ import { Tabs, Callout, Steps } from "nextra/components";
 
 # Zoom
 
-<Callout type="info">
-  At this time, Arcade does not offer a default Zoom Auth Provider. To use Zoom
-  auth, you must create a custom Auth Provider with your own Zoom OAuth 2.0
-  credentials as described below.
-</Callout>
-
 The Zoom auth provider enables tools and agents to call the Zoom API on behalf of a user.
 
 ### What's documented here
@@ -21,6 +15,38 @@ This auth provider is used by:
 
 ## Configuring Zoom auth
 
+You can either use Arcade's default Zoom OAuth provider (fastest way to get started), or configure your own Zoom OAuth provider for production.
+
+## Arcade's default Zoom OAuth provider
+
+Arcade provides a default Zoom OAuth provider (the Arcade-managed Zoom app) that you can use to quickly get started. This provider supports the scopes used by the Arcade Zoom MCP Server and is shared across all Arcade users.
+
+### Supported scopes
+
+The default Arcade Zoom OAuth provider supports the following scopes:
+
+- `meeting:read:invitation`
+- `meeting:read:list_upcoming_meetings`
+
+### Limitations
+
+The default provider has some limitations:
+
+- **Fixed scope list**: You can only use the scopes listed above
+- **Shared rate limits**: All Arcade users share the same rate limits
+- **Arcade branding**: Your users will see "Arcade" as the requesting application
+
+<Callout type="info">
+  For production use, we strongly recommend creating your own Zoom OAuth provider. This gives you:
+
+  - Full control over which scopes to request
+  - Dedicated rate limits for your application
+  - Your own branding in the OAuth consent screen
+  - Better security and compliance with your organization's policies
+</Callout>
+
+## Configuring your own Zoom OAuth provider
+
 <Callout type="info">
   When using your own app credentials, make sure you configure your project to
   use a [custom user
@@ -37,13 +63,13 @@ Before showing how to configure your Zoom app credentials, let's go through the
 ### Create a Zoom app
 
 - Follow Zoom's guide to [registering an app](https://developers.zoom.us/docs/integrations/create/) on the Zoom marketplace
-- Set the redirect URL to the redirect URL generated by Arcade (see below) and enable Strict Mode
+- Add the redirect URL generated by Arcade (see below) to **both** your Zoom app's **Redirect URL for OAuth** field and its **OAuth Allow List**, and enable Strict Mode. Zoom rejects the authorization request with an `Invalid redirect` error (`4,700`) if the URL is missing from either field.
 - Enable the Zoom features and permissions (scopes) that your app needs
 - Copy the client ID and client secret to use below
 
 Next, add the Zoom app to Arcade.
 
-## Configuring your own Zoom Auth Provider in Arcade
+### Setting up your Zoom OAuth provider in Arcade