Reworked static/style.css to follow the same visual language as
lumeex's back office (near-black background, cyan accent, gradient
pill buttons, translucent bordered panels) instead of the previous
generic dark-teal theme. Dropzones now use a dashed border while
empty, turning solid once a file is picked. Also fixes a stale CSS
selector (.dropzone label.tag) that never matched the actual markup
(a <span>), so the SDR/HDR tag labels were unstyled before.
Adds Gitea and GitHub repo links in the footer, using the same icons
and link pattern as lumeex.
Some users want the assembled HDR JPEG for somewhere other than
Instagram, where the exact 1080x1080/1080x1350/1080x566 match isn't
relevant. A checkbox on the form now lets the whole batch skip that
specific check. The SDR/HDR dimension-match check still always
applies, since that's a technical requirement for the gain map to
align, not an Instagram-specific rule.
Djeex