Fix IsHiddenPath treating current directory as hidden (closes #14)

IsHiddenPath(".") incorrectly returned true because path.Clean(".")
starts with a dot. Add explicit check for "." before the HasPrefix
check. Add test cases for ".", "./", and "./file.txt".

mfer/scanner.go

@@ -385,6 +385,9 @@ func (s *Scanner) ToManifest(ctx context.Context, w io.Writer, progress chan<- S
 // The path should use forward slashes.
 func IsHiddenPath(p string) bool {
 	tp := path.Clean(p)
+	if tp == "." {
+		return false
+	}
 	if strings.HasPrefix(tp, ".") {
 		return true
 	}

mfer/scanner_test.go

@@ -352,6 +352,9 @@ func TestIsHiddenPath(t *testing.T) {
 		{"/absolute/.hidden", true},
 		{"./relative", false}, // path.Clean removes leading ./
 		{"a/b/c/.d/e", true},
+		{".", false},          // current directory is not hidden (#14)
+		{"./", false},         // current directory with trailing slash
+		{"./file.txt", false}, // file in current directory
 	}
 
 	for _, tt := range tests {