054dd25079
Renames the app throughout: page titles, eyebrow/version labels, Docker startup banner, main.py's header docstring, and the repo links in the footer (now pointing at git.djeex.fr/Djeex/instameex and github.com/Djeex/instameex, matching the renamed Gitea/GitHub repos). Docker image and container are now named "instameex" too (docker/compose.yaml), replacing the old instagram-hdr naming. Adds the new logo: logo.svg is wired up as the favicon on both pages, and logo-long.svg replaces the plain-text "Instameex" eyebrow on the upload page as a properly sized wordmark. The startup banner box width was recalculated by hand for the new content (name plus Source:/Mirror: links instead of the old license/upstream-credit lines), verified against a real container rebuild so the border characters stay aligned. kostis-kounadis/instagram-hdr-assembler references are left alone throughout (README and banner): that's the separate upstream project this app's gain-map logic is adapted from, not this app's own name.