[InstagramBridge] Serve img as base64 data

[zenphonix]

Because of instagrams restrictive CORS same-origin policy images are not rendered when referenced directly.

This PR introduces fetching the image and serving it as base64 encoded data.

Fixes #2005

[github-actions]

Pull request artifacts

Bridge	Context	Status
Instagram	1 Username (current)	✔️
Instagram	1 Username (pr)	✔️
Instagram	2 Hashtag (current)	❌ Bridge returned error 401! (20509) ❌ Type: HttpException ❌ Message: https://www.instagram.com/graphql/query/?query_hash=9b498c08113f1e09617a1703c22b2f32&variables={"tag_name"%3A"beautifulday"%2C"first"%3A10} resulted in 401 Unauthorized
Instagram	2 Hashtag (pr)	❌ Bridge returned error 401! (20509) ❌ Type: HttpException ❌ Message: https://www.instagram.com/graphql/query/?query_hash=9b498c08113f1e09617a1703c22b2f32&variables={"tag_name"%3A"beautifulday"%2C"first"%3A10} resulted in 401 Unauthorized
Instagram	3 Location (current)	⚠️ The feed has no items
Instagram	3 Location (pr)	⚠️ The feed has no items

last change: Wednesday 2026-02-25 13:50:40

[zenphonix]

It would be good to downscale the images to 540x540 to improve loading times

[zenphonix]

One quick way to resize images would be

$imageSmall = imagescale($image,540);

but this would require PHP GD library. Is it feasible to include GD in into rss-bridge?
I could imagine that other bridges might benefit from GD as well.

[zenphonix]

Last two commits include these changes:

• add php-gd installation to dockerfile
• rescale instagram images to 540pt (50%) before encoding as data:image/png;base64

[zenphonix]

Need to add a conditional test in order to avoid exception

imagescale(): Argument #1 ($image) must be of type GdImage, bool given