Use Featured Hashtags as content filters displayed immediately above the profile timeline

[FediVideos]

Pitch

Put the featured hashtags above the profile timeline as a set of filters, so that people notice them even if they're on a mobile web view, and so that people intuitively understand what they do.

See the screenshot for an example, this is what the original plan was for featured hashtags and it is a crying shame it wasn't implemented. The code for it exists already, as it was tested for a short while on mastodon.online (which is where I took the screenshot).

Motivation

This would solve the major problems with Featured Hashtags:

• It's not immediately obvious what tags at the side actually are. By putting them above timeline it makes it intuitively obvious what they are and what they do.
• Current featured tags are totally hidden in mobile web view, putting tags above timeline makes them visible to everyone even on mobile devices.
• Current featured tags are in same place as trending tags, people ignore/confuse them due to this, putting tags above timeline make them obviously a separate feature.

[jasonHYLam]

I'm happy to be assigned to this!

[jasonHYLam]

I would really love to work on this issue, unfortunately I'm running into errors when setting up GitHub Codespaces for Mastodon. So somebody else can take up this issue!

If someone wants to help me with my issue, I'll give some context. After using this link to create a new Codespace I get an error message saying that the build fails.
I check the creation.log which shows a bunch of NoSpaceOnDeviceError. I then added to my devcontainer.json using PR 26382.
After that, I get another error:

2024-04-27 14:03:53.623Z: Fetching tzinfo-data 1.2024.12024-04-27 14:03:53.628Z: 
2024-04-27 14:03:53.654Z: Installing tzinfo-data 1.2024.12024-04-27 14:03:53.667Z: 
2024-04-27 14:03:59.763Z: The installation path is insecure. Bundler cannot continue.
/workspaces/mastodon/vendor/bundle/ruby/3.2.0/gems is world-writable (without
sticky bit).
Bundler cannot safely replace gems in world-writeable directories due to
potential vulnerabilities.
Please change the permissions of this directory or choose a different install
2024-04-27 14:03:59.772Z: path.
2024-04-27 14:03:59.857Z: postCreateCommand failed with exit code 38. Skipping any further user-provided commands.

If there is a fix for this please let me know :)