Edit Theme images without CLI?

All I want to do is edit the header image and template files of my Quark themed site. Can I add/remove/edit that image (and css, etc) without CLI? Is there a way to do it via the Admin Panel or a Plugin with the Admin Panel?
It is possible to connect my Grav site to GitHub and make these image edits?

My goal here is to have the ability to edit the site & theme from any computer, and not be dependent on a CLI that's tied to a specific SSH tunnel that's tied to a specific computer. Does that make sense?

Hi!

@miller.nw:
Does that make sense?

I'm pleased to inform you, that it is not only reasonable (I actually prefer to work this way too!), but also rather easy to do :)

• First of all, I'm not entirely sure what do you mean exactly by header image; if you mean site logos, you can upload them in Quark settings in Admin - /admin/themes/quark:
  
  If you meant hero image (huge one on top of every page), that's also simple, you just upload it on page edit form, and if you don't specifically set it otherwise, it will use first upload.
• if you want to use your own assets, templates etc., most likely creating custom subtheme that inherits from Quark (so you add only those templates that are changed) as explained in documentation will be way better!
  • you can upload your custom theme in Admin as a .zip archive, either from your local machine, or from some online source (i.e. release on Github-like service)
  • my personal favourite, though, is a git based workflow using GitSync plugin, which allows you to sync custom themes or plugins, but configs and contents as well! It's really neat and I use it a lot!
    Hope this helps, and you'll enjoy working with Grav as much as I do!

Oh man, thank you so much!

Based on what you explained to me I started playing around with other templates and realized the hero image would load (using the first image loaded to a page using the form editor) for the Aerial Theme but not for the Quark Theme.

For reasons I cannot figure out I cannot get the Quark Theme to display a hero image. I've tried a lot of different things including calling out hero_image in the frontmatter.

Any ideas of what I'm doing wrong? Here's the site I'm using for testing: https://clarity-collab-main-site-7-2020.i.claritycollaborative.com/hero-image-test

I see that it works in the modular tho :)
What is the page's template? I see that it does not render hero block at all...
As per Quark docs, hero works only in modular, blog and item pages. Is it possible that this page is a default type?