fix(git): don't push an unborn HEAD from mkrep's default remote templates

mkrep only ever runs git init, never a commit, so a freshly created
repo has no HEAD yet. The gitea/gitlab default templates chained
`git push -u origin HEAD` unconditionally after linking the remote,
which fails immediately regardless of the remote ("src refspec HEAD
does not match any") -- reproduced by a real user hitting it on the
first mkrep --server call. Guard the push on HEAD actually resolving
to a commit; skipping it is the correct outcome (nothing to push yet),
and a real push failure once a commit exists still propagates.

functions/_mkrep_default_remote_cmd.fish

@@ -7,7 +7,12 @@
 # DESCRIPTION
 #   Prints the default remote-create command template for <type>, used by
 #   mkrep's --server flow when $MKREP_REMOTE_CMD is unset. Same {name},
-#   {user}, {server} placeholders as --new-remote.
+#   {user}, {server} placeholders as --new-remote. gitlab/gitea guard
+#   their final push on HEAD actually resolving to a commit -- mkrep only
+#   ever runs `git init`, so a fresh call has no commit yet, and
+#   `git push -u origin HEAD` errors on an unborn HEAD regardless of the
+#   remote. Skipping the push there is silent success, not a swallowed
+#   failure: once a commit exists, a real push failure still propagates.
 #
 # ARGUMENTS
 #   type   gitea, gitlab, or github
@@ -23,9 +28,9 @@ function _mkrep_default_remote_cmd --argument-names type
         case github
             echo 'gh repo create {name} --private --source=. --remote=origin --push'
         case gitlab
-            echo 'glab repo create {name} --private --skipGitInit && git remote add origin {server}/{user}/{name}.git && git push -u origin HEAD'
+            echo 'glab repo create {name} --private --skipGitInit && git remote add origin {server}/{user}/{name}.git && if git rev-parse --verify -q HEAD >/dev/null 2>&1; git push -u origin HEAD; end'
         case gitea
-            echo 'tea repos create --name {name} --private && git remote add origin {server}/{user}/{name}.git && git push -u origin HEAD'
+            echo 'tea repos create --name {name} --private && git remote add origin {server}/{user}/{name}.git && if git rev-parse --verify -q HEAD >/dev/null 2>&1; git push -u origin HEAD; end'
         case '*'
             return 1
     end

functions/mkrep.fish

@@ -104,14 +104,17 @@
 #
 #   Starting points for $MKREP_REMOTE_CMD, one per host CLI -- each assumes
 #   that tool is already installed and authenticated, creates a private
-#   repo under the caller's own account, and pushes the initial commit.
-#   These are also mkrep's built-in defaults for --server/$GIT_SERVER when
-#   $MKREP_REMOTE_CMD is unset. gh supports a one-shot
-#   --source/--remote/--push; glab and tea's create commands do not, so
-#   they are chained with the git commands that do the linking:
+#   repo under the caller's own account, and pushes it if there is
+#   already a commit to push (mkrep itself only runs git init, so a
+#   freshly created repo has none yet -- pushing an unborn HEAD is a
+#   guaranteed error regardless of the remote, so the push is skipped
+#   rather than attempted). These are also mkrep's built-in defaults for
+#   --server/$GIT_SERVER when $MKREP_REMOTE_CMD is unset. gh supports a
+#   one-shot --source/--remote/--push; glab and tea's create commands do
+#   not, so they are chained with the git commands that do the linking:
 #     GitHub (gh):   gh repo create {name} --private --source=. --remote=origin --push
-#     GitLab (glab): glab repo create {name} --private --skipGitInit && git remote add origin {server}/{user}/{name}.git && git push -u origin HEAD
-#     Gitea (tea):   tea repos create --name {name} --private && git remote add origin {server}/{user}/{name}.git && git push -u origin HEAD
+#     GitLab (glab): glab repo create {name} --private --skipGitInit && git remote add origin {server}/{user}/{name}.git && if git rev-parse --verify -q HEAD >/dev/null 2>&1; git push -u origin HEAD; end
+#     Gitea (tea):   tea repos create --name {name} --private && git remote add origin {server}/{user}/{name}.git && if git rev-parse --verify -q HEAD >/dev/null 2>&1; git push -u origin HEAD; end
 function mkrep --description 'Create a directory, cd into it, and git init it'
     __fish_palette