feat(canonical): validate profile name, apply env-var substitution before render

internal/cli/init_test.go

@@ -49,3 +49,57 @@ func TestInitImportWritesCanonical(t *testing.T) {
 	_, err := os.Stat(filepath.Join(root, ".git"))
 	require.NoError(t, err)
 }
+
+func makeStubReg() *adapter.Registry {
+	reg := adapter.NewRegistry()
+	reg.Register(&importableAdapter{
+		name: "stub",
+		res:  &adapter.ImportResult{},
+	})
+	return reg
+}
+
+// TestInitRefusesOverwriteWithoutForce: second init without --force must error.
+func TestInitRefusesOverwriteWithoutForce(t *testing.T) {
+	root := t.TempDir()
+	home := t.TempDir()
+
+	// First init — should succeed.
+	cmd := NewInit(makeStubReg())
+	cmd.SetArgs([]string{"--root", root, "--home", home, "--from", "stub", "--no-prompt"})
+	require.NoError(t, cmd.Execute())
+
+	// Second init — must fail without --force.
+	cmd2 := NewInit(makeStubReg())
+	cmd2.SetArgs([]string{"--root", root, "--home", home, "--from", "stub", "--no-prompt"})
+	err := cmd2.Execute()
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "already initialised")
+	assert.Contains(t, err.Error(), "--force")
+}
+
+// TestInitForcePreservesExistingProfile: --force re-imports but does NOT overwrite imported.yaml.
+func TestInitForcePreservesExistingProfile(t *testing.T) {
+	root := t.TempDir()
+	home := t.TempDir()
+
+	// First init writes placeholder profile.
+	cmd := NewInit(makeStubReg())
+	cmd.SetArgs([]string{"--root", root, "--home", home, "--from", "stub", "--no-prompt"})
+	require.NoError(t, cmd.Execute())
+
+	// User edits the profile.
+	profPath := filepath.Join(root, "profiles", "imported.yaml")
+	userEdit := []byte("name: imported\ngateway:\n  url: \"https://my.gateway\"\n  token: \"tok\"\n  default_model: \"m\"\nmodels: []\n")
+	require.NoError(t, os.WriteFile(profPath, userEdit, 0o600))
+
+	// Re-init with --force.
+	cmd2 := NewInit(makeStubReg())
+	cmd2.SetArgs([]string{"--root", root, "--home", home, "--from", "stub", "--no-prompt", "--force"})
+	require.NoError(t, cmd2.Execute())
+
+	// User edits must be preserved.
+	got, err := os.ReadFile(profPath)
+	require.NoError(t, err)
+	assert.Equal(t, string(userEdit), string(got))
+}