feat: S3 credential resolution via APOS_S3_SECRET or AWS default chain (#256)

feat: S3 credential resolution via APOS_S3_SECRET or AWS default chain

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
Refactors S3 credential configuration in the uploadfs module by
introducing a centralized uploadfsOptions object populated from
environment variables. It sets HTTPS flag, CDN settings,
bucket/region/endpoint/style, and conditionally adds secret and key when
APOS_S3_SECRET is present. Credentials otherwise rely on the AWS default
credential chain via omission of inline keys for uploads.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

---------

Co-authored-by: Ihor Masechko <ihormasechko@Ihors-MacBook-Air.local>

Author: IhorMasechko

website/modules/@apostrophecms/uploadfs/index.js

@@ -1,24 +1,29 @@
 const { getEnv } = require('../../../utils/env');
 
+const aposS3Secret = process.env.APOS_S3_SECRET;
+const aposS3Https = getEnv('APOS_S3_HTTPS');
+
+const uploadfsOptions = {
+  storage: 's3',
+  bucket: getEnv('APOS_S3_BUCKET'),
+  region: getEnv('APOS_S3_REGION'),
+  endpoint: getEnv('APOS_S3_ENDPOINT'),
+  style: getEnv('APOS_S3_STYLE'),
+  https: aposS3Https.toLowerCase() === 'true',
+  cdn: {
+    enabled: true,
+    url: getEnv('APOS_CDN_URL'),
+  },
+};
+
+if (aposS3Secret) {
+  uploadfsOptions.secret = aposS3Secret;
+  uploadfsOptions.key = getEnv('APOS_S3_KEY');
+}
+
 const res = {
   options: {
-    uploadfs: {
-      storage: 's3',
-      // Get your credentials at aws.amazon.com
-      secret: getEnv('APOS_S3_SECRET'),
-      key: getEnv('APOS_S3_KEY'),
-      // Bucket name created on aws.amazon.com
-      bucket: getEnv('APOS_S3_BUCKET'),
-      // Region name for endpoint
-      region: getEnv('APOS_S3_REGION'),
-      endpoint: getEnv('APOS_S3_ENDPOINT'),
-      style: getEnv('APOS_S3_STYLE'),
-      https: getEnv('APOS_S3_HTTPS'),
-      cdn: {
-        enabled: true,
-        url: getEnv('APOS_CDN_URL'),
-      },
-    },
+    uploadfs: uploadfsOptions,
   },
 };