feat(core): improve auth handling (#15271)

fix #15270
fix #15260
fix #15257


#### PR Dependency Tree


* **PR #15271** 👈

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packages/backend/server/src/plugins/oauth/providers/def.ts

@@ -6,6 +6,7 @@ import {
   InvalidOauthResponse,
   OnEvent,
   safeFetch,
+  type SafeFetchOptions,
 } from '../../../base';
 import { OAuthProviderName } from '../config';
 import { OAuthProviderFactory } from '../factory';
@@ -79,6 +80,15 @@ export abstract class OAuthProvider {
     return false;
   }
 
+  protected fetchOptions(_url: string | URL): SafeFetchOptions {
+    return {
+      timeoutMs: 10_000,
+      maxRedirects: 3,
+      maxBytes: 1024 * 1024,
+      allowedHeaders: ['authorization', 'content-type', 'accept'],
+    };
+  }
+
   protected async fetchJson<T>(
     url: string,
     init?: RequestInit,
@@ -87,12 +97,7 @@ export abstract class OAuthProvider {
     const response = await safeFetch(
       url,
       { ...init, headers: { ...init?.headers, Accept: 'application/json' } },
-      {
-        timeoutMs: 10_000,
-        maxRedirects: 3,
-        maxBytes: 1024 * 1024,
-        allowedHeaders: ['authorization', 'content-type', 'accept'],
-      }
+      this.fetchOptions(url)
     );
 
     const body = await response.text();