Fix goconst linter issues (bd-116)

- Use windowsOS constant in reinit_test.go
- Use testIssueBD1 constant in compact_test.go and counter_sync_test.go
- Merged duplicate bd-126 into bd-116

cmd/bd/reinit_test.go

@@ -438,7 +438,7 @@ func writeJSONL(path string, issues []*types.Issue) error {
 // normalizeGitPath converts a path to use forward slashes for git compatibility
 // Git always uses forward slashes internally, even on Windows
 func normalizeGitPath(path string) string {
-	if runtime.GOOS == "windows" {
+	if runtime.GOOS == windowsOS {
 		return filepath.ToSlash(path)
 	}
 	return path