fix: handle unborn HEAD branch creation

- Create orphan branches when HEAD does not exist yet\n- Use current branch as the default branch base in the toolbar\n- Keep push disabled for remote-less repos\n\nQuality gates: vitest repositories-settings-tab (passed); api pytest blocked by missing fastapi in environment

apps/api/src/utils/git_control.py

@@ -121,6 +121,13 @@ def create_branch(repo_path: str, name: str, base_branch: str = "HEAD") -> None:
     Raises:
         RuntimeError: If branch creation fails
     """
+    if base_branch == "HEAD":
+        try:
+            _run_git_command(repo_path, "rev-parse", "--verify", "HEAD")
+        except RuntimeError:
+            _run_git_command(repo_path, "checkout", "--orphan", name)
+            return
+
     _run_git_command(repo_path, "branch", name, base_branch)
 
 

apps/api/tests/unit/test_git_repository_working_clones.py

@@ -4,6 +4,7 @@ import pytest
 from fastapi import HTTPException
 
 from src.api.git_repositories import _clone_working_repository, _init_working_repository
+from src.utils.git_control import create_branch
 
 
 def test_clone_working_repository_uses_normal_clone() -> None:
@@ -44,3 +45,14 @@ def test_init_working_repository_falls_back_to_symbolic_ref() -> None:
     assert run_mock.call_args_list[0].args[0] == ["git", "init", "-b", "main", "/tmp/new-repo"]
     assert run_mock.call_args_list[1].args[0] == ["git", "init", "/tmp/new-repo"]
     assert run_mock.call_args_list[2].args[0] == ["git", "-C", "/tmp/new-repo", "symbolic-ref", "HEAD", "refs/heads/main"]
+
+
+def test_create_branch_uses_orphan_checkout_when_head_is_unborn() -> None:
+    verify_head = Mock(returncode=128, stderr="fatal: Needed a single revision")
+    checkout_orphan = Mock(returncode=0, stderr="")
+
+    with patch("src.utils.git_control._run_git_command", side_effect=[verify_head, checkout_orphan]) as run_mock:
+        create_branch("/tmp/new-repo", "feature/test")
+
+    assert run_mock.call_args_list[0].args[1:] == ("rev-parse", "--verify", "HEAD")
+    assert run_mock.call_args_list[1].args[1:] == ("checkout", "--orphan", "feature/test")

apps/web/src/components/git-toolbar.tsx

@@ -112,7 +112,7 @@ export const GitToolbar = ({
     if (!newBranchName.trim()) return;
     setLoading(true);
     try {
-      await createBranch(projectId, repoId, newBranchName, newBranchBase || "HEAD");
+      await createBranch(projectId, repoId, newBranchName, newBranchBase || currentBranch || "HEAD");
       setShowNewBranch(false);
       setNewBranchName("");
       setNewBranchBase("");
@@ -131,6 +131,8 @@ export const GitToolbar = ({
     status.untracked.length > 0
   );
 
+  const canSync = hasRemote;
+
   return (
     <div className="git-toolbar">
       {error && <div className="toolbar-error">{error}</div>}
@@ -169,7 +171,7 @@ export const GitToolbar = ({
           <button
             className="toolbar-button"
             onClick={handleFetch}
-            disabled={loading || !hasRemote}
+            disabled={loading || !canSync}
             type="button"
           >
             <Icon name="fetch" size="sm" /> Fetch
@@ -177,7 +179,7 @@ export const GitToolbar = ({
           <button
             className="toolbar-button"
             onClick={handlePull}
-            disabled={loading || !hasRemote}
+            disabled={loading || !canSync}
             type="button"
           >
             <Icon name="pull" size="sm" /> Pull
@@ -186,7 +188,7 @@ export const GitToolbar = ({
           <button
             className="toolbar-button"
             onClick={handlePush}
-            disabled={loading || !status?.ahead}
+            disabled={loading || !canSync || !status?.ahead}
             type="button"
           >
             <Icon name="push" size="sm" /> Push