fix(augment): make hook installation transactional

cmd/elydora/augment_cli_test.go

@@ -0,0 +1,66 @@
+package main
+
+import (
+	"errors"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+func TestAugmentCLIPreflightPreservesMalformedSettings(t *testing.T) {
+	homeDir := filepath.Join(t.TempDir(), "home")
+	settingsPath := filepath.Join(homeDir, ".augment", "settings.json")
+	keyPath := filepath.Join(t.TempDir(), "private.key")
+	if err := os.MkdirAll(filepath.Dir(settingsPath), 0700); err != nil {
+		t.Fatalf("create Auggie settings directory: %v", err)
+	}
+	if err := os.WriteFile(settingsPath, []byte("{ malformed"), 0600); err != nil {
+		t.Fatalf("write malformed Auggie settings: %v", err)
+	}
+	privateKey := "BwcHBwcHBwcHBwcHBwcHBwcHBwcHBwcHBwcHBwcHBwc"
+	if err := os.WriteFile(keyPath, []byte(privateKey+"\n"), 0600); err != nil {
+		t.Fatalf("write private key: %v", err)
+	}
+	command := exec.Command(
+		"go",
+		"run",
+		".",
+		"install",
+		"--agent",
+		"augment",
+		"--org-id",
+		"org-1",
+		"--agent-id",
+		"agent-1",
+		"--private-key-file",
+		keyPath,
+		"--kid",
+		"kid-1",
+		"--base-url",
+		"https://api.elydora.com",
+	)
+	command.Env = append(
+		os.Environ(),
+		"HOME="+homeDir,
+		"USERPROFILE="+homeDir,
+	)
+	output, err := command.CombinedOutput()
+	if err == nil || !strings.Contains(
+		string(output),
+		"parse Auggie user settings",
+	) {
+		t.Fatalf("CLI preflight result = %v\n%s", err, output)
+	}
+	raw, readErr := os.ReadFile(settingsPath)
+	if readErr != nil || string(raw) != "{ malformed" {
+		t.Fatalf("malformed settings changed: %q, %v", raw, readErr)
+	}
+	if _, statErr := os.Lstat(filepath.Join(homeDir, ".elydora")); !errors.Is(
+		statErr,
+		os.ErrNotExist,
+	) {
+		t.Fatalf("runtime directory created during failed preflight: %v", statErr)
+	}
+}