toolsSpecFromEnv function
Parses the FA_TOOLS env twin of the --tools flag: the same csv
spec, for Docker/headless hosts that cannot pass flags. Absent or empty
yields null (no runtime intent); a malformed value throws
ConfigException naming the bad token.
Implementation
ToolsConfig? toolsSpecFromEnv(Map<String, String> env) {
final spec = env['FA_TOOLS'];
if (spec == null || spec.trim().isEmpty) return null;
return parseToolsSpec(spec);
}