Fs-serve import graph awareness

Editor assessment

`feat: fs-serve import graph awareness` is compressed project shorthand — awareness of the import graph within the file-serving allowlist logic — that outsiders cannot decode without the diff or the linked pull request. Feat fits a security-relevant behavior change, and no scope is used. No body unpacks the phrase into concrete behavior — what requests are now checked and how — so the message communicates a slogan rather than a change. Understandable only with effort: valid but mediocre, capped at acceptable.