fix(02): resolve symlinks before fixture and vars path checks (WR-07)

Co-authored-by: Cursor <cursoragent@cursor.com>

tide/manifest.go

@@ -192,6 +192,9 @@ func validateFixturePath(p string) error {
 	if clean == ".." || strings.HasPrefix(clean, "../") {
 		return fmt.Errorf("fixture %q escapes the fixture directory", p)
 	}
+	if _, err := resolvePath(p); err != nil {
+		return fmt.Errorf("fixture %q: %w", p, err)
+	}
 	return nil
 }