fix(proxy): handle more content-disposition edge cases (#3100)

<!-- Describe the problem and your solution --> 
Refactored the response handling to cover more edge cases. Instead of
checking if the `content-disposition` header is exactly equal to
`attachment`, we now check if it includes `attachment` or `inline`,
allowing for more flexibility. This change improves the handling of
different content types by considering both attachment and inline
dispositions.
<!-- Issue ticket number and link (if applicable) -->

<!-- Testing instructions (skip if just adding/editing providers) -->
Initially this was producing a malformed response with the dropbox and
front providers, but after the fix, it works as expected.

---------

Co-authored-by: Hassan Wari <[email protected]>
Co-authored-by: Khaliq <[email protected]>

packages/server/lib/controllers/proxy.controller.ts

@@ -265,13 +265,17 @@ class ProxyController {
             }
         });
 
-        const contentType = responseStream.headers['content-type'];
-        const isJsonResponse = contentType && contentType.includes('application/json');
-        const isChunked = responseStream.headers['transfer-encoding'] === 'chunked';
-        const isEncoded = Boolean(responseStream.headers['content-encoding']);
-        const isAttachment = responseStream.headers['content-disposition'] === 'attachment';
+        const contentType = responseStream.headers['content-type'] || '';
+        const contentDisposition = responseStream.headers['content-disposition'] || '';
+        const transferEncoding = responseStream.headers['transfer-encoding'] || '';
+        const contentEncoding = responseStream.headers['content-encoding'] || '';
 
-        if (isChunked || isEncoded || isAttachment) {
+        const isJsonResponse = contentType.includes('application/json');
+        const isChunked = transferEncoding === 'chunked';
+        const isEncoded = Boolean(contentEncoding);
+        const isAttachmentOrInline = /^(attachment|inline)(;|\s|$)/i.test(contentDisposition);
+
+        if (isChunked || isEncoded || isAttachmentOrInline) {
             const passThroughStream = new PassThrough();
             responseStream.data.pipe(passThroughStream);
             passThroughStream.pipe(res);