Let a machine say what it is for, and give Firefox its face back

Phase 4: the optional application categories, and the Firefox chrome.

Everything Panama installed until now was what every machine gets, which meant a
work laptop acquired emulators and a desktop that wanted Steam had to be told
about it by hand. The interview now offers the categories in
setup/packages/extras/ as a checklist -- gaming, creative, communication,
virtualization -- and nothing is preselected, because a default here installs
applications nobody chose on a machine whose owner answered a question they
thought was about something else.

A category is one file, and a category mixes both package managers because the
applications do: Steam is in RPM Fusion, Slack publishes only a flatpak. So a
bare line is a dnf package and a flatpak: line is a Flathub ID, and one file
holds the whole answer rather than splitting each category across two. The menu
is read from the directory rather than written down, so adding a category is
adding a file. Every name in all four was resolved against the actual
repositories before being written down, and the contract re-resolves them --
the point of admitting applications one at a time is that they stay installable,
and a typo here fails on somebody else's machine, not this one.

Firefox is declared, and its chrome is Edge-Frfox, vendored into config/firefox.
sunhat carried that theme with no license and no attribution; it is MIT, and now
it says so and says whose it is.

It is the only piece of Panama's configuration that does not go to a path this
repository chooses. Firefox owns the profile directory, names it with a random
salt, and does not create one until the browser has been run -- so link-dotfiles
finds or creates a profile and links both halves into it. Both, or neither works:
chrome/ is the CSS and user.js sets the preference that makes Firefox read chrome/
at all, without which the theme is a directory of dead files.

Two assumptions there were wrong, and the contract exists for both. Firefox has
moved to the XDG directories -- the profile root is ~/.config/mozilla/firefox on
this build, not ~/.mozilla/firefox, and writing to the wrong one themes nothing
and says nothing about it. And -CreateProfile turns out to be non-interactive, so
a fresh machine gets the theme on the first install rather than the second. The
contract runs link-dotfiles for real against a throwaway home with no profile in
it and looks at what came out; it was checked by pointing the search at the
legacy path only and watching it fail.

Also: the enrolment/enrollment spellings from the last commit are corrected. This
repository is US-spelled everywhere else -- color 1131 times against colour never
-- and consistency in prose is worth as much as it is in code.

Claude-Session: https://claude.ai/code/session_01NvgBuSWB5sE43yWmg21ozj

config/firefox/chrome/icons/fullscreen-exit.svg

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