feat: add local skill store and targets

internal/targets/junction_windows.go

@@ -0,0 +1,69 @@
+package targets
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+)
+
+func CreateJunction(linkPath, targetPath string) error {
+	if err := os.MkdirAll(filepath.Dir(linkPath), 0o755); err != nil {
+		return err
+	}
+	cmd := exec.Command("cmd.exe", "/c", "mklink", "/J", linkPath, targetPath)
+	out, err := cmd.CombinedOutput()
+	if err != nil {
+		return fmt.Errorf("create junction failed: %w: %s", err, strings.TrimSpace(string(out)))
+	}
+	return nil
+}
+
+func ReadJunctionTarget(linkPath string) (string, error) {
+	if _, err := os.Lstat(linkPath); err != nil {
+		return "", err
+	}
+	target, err := os.Readlink(linkPath)
+	if err == nil && target != "" {
+		return cleanWindowsLinkTarget(target), nil
+	}
+	evaluated, evalErr := filepath.EvalSymlinks(linkPath)
+	if evalErr != nil {
+		return "", evalErr
+	}
+	if samePath(evaluated, linkPath) {
+		return "", errors.New("path is not a junction")
+	}
+	return evaluated, nil
+}
+
+func RemoveJunction(linkPath string) error {
+	if err := os.Remove(linkPath); err == nil || errors.Is(err, os.ErrNotExist) {
+		return nil
+	}
+	cmd := exec.Command("cmd.exe", "/c", "rmdir", linkPath)
+	out, err := cmd.CombinedOutput()
+	if err != nil {
+		return fmt.Errorf("remove junction failed: %w: %s", err, strings.TrimSpace(string(out)))
+	}
+	return nil
+}
+
+func cleanWindowsLinkTarget(target string) string {
+	target = strings.TrimPrefix(target, `\??\`)
+	return filepath.Clean(target)
+}
+
+func samePath(left, right string) bool {
+	leftAbs, leftErr := filepath.Abs(cleanWindowsLinkTarget(left))
+	rightAbs, rightErr := filepath.Abs(cleanWindowsLinkTarget(right))
+	if leftErr == nil {
+		left = leftAbs
+	}
+	if rightErr == nil {
+		right = rightAbs
+	}
+	return strings.EqualFold(filepath.Clean(left), filepath.Clean(right))
+}