Point links at the new git host

GitHub went dark with the account suspension on 2026-09-20 and GitLab was
retired on 2026-09-22, so links to either no longer resolve. Repository,
file, release and download links now point at git.coffeylabs.org, images
at registry.coffeylabs.org, and old GitHub issue and pull request links at
coffey-labs/ihasmail-github-archive, whose numbers match GitHub's.

.env.example

@@ -75,7 +75,7 @@ APP_NAME=ihasmail
 # you have patched it, point this at your own tree. Shown on the sign-in page
 # and in Settings > About. INBUXA's webmail is itself a modified ihasmail, so
 # the default is this fork.
-SOURCE_URL=https://github.com/inbuxa/ihasmail-inbuxa
+SOURCE_URL=https://git.coffeylabs.org/inbuxa/ihasmail-inbuxa
 
 # ---- Settings this installation decides (all optional) ----
 #