feat(library): exclude configured folders from scanning and analysis

services/api/internal/library/exclusions.go

@@ -0,0 +1,50 @@
+package library
+
+import (
+	"path"
+	"strings"
+	"unicode/utf8"
+
+	"pipu/api/internal/platform/apperr"
+)
+
+// normalizeExcludedDirs accepts literal paths relative to the storage root, not globs.
+func normalizeExcludedDirs(dirs []string) ([]string, error) {
+	invalid := func() ([]string, error) {
+		return nil, apperr.Validation("excluded_dirs", "validation.excluded_dirs_invalid", "use up to 100 relative folder paths without .., one per entry", nil)
+	}
+	if len(dirs) > 100 {
+		return invalid()
+	}
+	out := []string{}
+	seen := map[string]bool{}
+	for _, dir := range dirs {
+		dir = strings.ReplaceAll(strings.TrimSpace(dir), "\\", "/")
+		if dir == "" || strings.HasPrefix(dir, "/") || strings.ContainsAny(dir, "\x00\r\n") || utf8.RuneCountInString(dir) > 1000 || (len(dir) > 1 && dir[1] == ':') {
+			return invalid()
+		}
+		for _, part := range strings.Split(dir, "/") {
+			if part == ".." {
+				return invalid()
+			}
+		}
+		dir = path.Clean(dir)
+		if dir == "." {
+			return invalid()
+		}
+		if !seen[dir] {
+			out = append(out, dir)
+			seen[dir] = true
+		}
+	}
+	return out, nil
+}
+
+func pathExcluded(rel string, dirs []string) bool {
+	for _, dir := range dirs {
+		if rel == dir || strings.HasPrefix(rel, dir+"/") {
+			return true
+		}
+	}
+	return false
+}