Install beside COSMIC instead of replacing it

The packages could not be installed. Claiming the cosmic-* names put 62 files
in conflict with 25 distribution packages -- something dnf's depsolve never
reports, because it shows up only in rpm's transaction check -- and the only
way to satisfy that was Conflicts against all 25, which erases cosmic-greeter.
On a stock Fedora COSMIC that is the display manager, so the machine comes
back to a text console with no way to log in and no session to fall back to.

So the fork ships what it actually forks. The three changed binaries take
hyprcosmic-comp, hyprcosmic-session and hyprcosmic-conf, the workflow reduces
the staged tree to those plus this fork's own assets, and cosmic-settings, the
portal, the OSD and the rest come from the distribution at the version it
tested them at. No Conflicts, no Provides, nothing erased, and the stock
COSMIC entry stays on the greeter's menu to fall back to.

Debian is the exception and keeps the whole desktop, because COSMIC is not
packaged there in any suite: there is nothing to depend on and nothing to
install beside. Its stock session entry is dropped instead, since start-cosmic
execs the cosmic-session this rename takes away.

config/autostart

@@ -23,7 +23,7 @@
 # A malformed edit is not fatal. It is reported to the session log and the last
 # good configuration stays in place, so a typo cannot leave you at a broken
 # desktop -- fix the file and the next save applies.
-cosmic-conf watch
+hyprcosmic-conf watch
 
 # The bar. The layout is shared and lives under /usr/share, but the stylesheet
 # has to be per-user: it imports a sibling theme.css holding the installed HyDE