Point GitHub URLs at omacom/omarchy instead of basecamp/omarchy

The repo moved to the omacom org. GitHub redirects the old URLs, but
`omarchy channel set dev` was still cloning from basecamp/omarchy, which
left every dev checkout with a stale origin remote that confuses gh
(pr create fails with "No commits between omacom:quattro and
basecamp:<branch>"). Update the clone URL, the quattro upgrade tarball,
the update-confirm release link, the systemd Documentation link, and
the manual.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LSFKDatumRZHB8zqk5CP5C

default/hypr/apps/jetbrains.lua

@@ -1,2 +1,2 @@
--- Disable mouse focus (see https://github.com/basecamp/omarchy/pull/5183#issuecomment-4189299971).
+-- Disable mouse focus (see https://github.com/omacom/omarchy/pull/5183#issuecomment-4189299971).
 o.window("^(jetbrains-.*)$", { no_follow_mouse = true })