docs: unify the Account Center social callback URL (#1485)

* docs: unify the Account Center social callback URL

The Account Center now initiates social linking with the same
/callback/:connectorId URI as the sign-in flow, and Logto Core routes
the callback by the OAuth state prefix. Only one redirect URI needs to
be registered with the social provider.

* docs: describe the social callback URL as-is

* docs: drop the redundant callback URL emphasis

Author: wangsijie

docs/end-user-flows/account-settings/by-account-center-ui.mdx

@@ -181,17 +181,13 @@ Leave the field empty (or set `deleteAccountUrl` to `null`) to hide the account
 
 ## Social connection callback URL \{#social-connection-callback-url}
 
-When a user links a social account from the Account Center, Logto uses a different redirect URI than the regular sign-in flow. The Account Center callback URL has the following format:
+Linking a social account from the Account Center uses the connector's callback URL:
 
 ```
-https://[your-tenant-endpoint]/account/callback/social/{connectorId}
+https://[your-tenant-endpoint]/callback/{connectorId}
 ```
 
-Where `{connectorId}` is the ID of the social connector (you can find it in <CloudLink to="/connectors/social">Console > Connectors > Social connectors</CloudLink>).
-
-:::caution
-You must add this URL to the **Authorized redirect URIs** (or equivalent) list in your social provider's developer console (Google, GitHub, Facebook, etc.) **in addition to** the standard sign-in callback URL `https://[your-tenant-endpoint]/callback/{connectorId}`. Otherwise, the link flow will fail with a redirect URI mismatch error.
-:::
+Where `{connectorId}` is the ID of the social connector. This is the **Callback URI** shown on the connector details page in <CloudLink to="/connectors/social">Console > Connectors > Social connectors</CloudLink>, which you register with your social provider when [setting up the connector](/connectors/social-connectors/).
 
 ## Security considerations \{#security-considerations}